Contract analysis

I. ENGAGEMENT AND SCOPE Calderwood & Harkness LLP has acted as counsel to the Company in connection with the preparation and filing of the Registration Statement on Form S-1 (File No. 333-276841) (together with all amendments and supplements thereto, the "Registration Statement"), which was filed with the Securities and Exchange Commission (the "SEC" or the "Commission") under the Securities Act of 1933, as amended (

II. DOCUMENTS AND RECORDS EXAMINED In rendering the opinions expressed herein, we have examined originals, or copies identified to our satisfaction as being true and complete copies of originals, of the following documents, instruments, records, and certificates:

1. The Amended and Restated Certificate of Incorporation of the Company, as filed with the Secretary of State of the State of Delaware on February 13, 2024 (the "Certificate of Incorporation"), which authorizes 400,000,000 shares of Common Stock, par value $0.001 per share, and 50,000,000 shares of preferred stock, par value $0.001 per share (the "Preferred Stock"), and which sets forth the rights, preferences, privi

2. The Amended and Restated Bylaws of the Company, adopted by the Board of Directors of the Company (the "Board") on February 8, 2024, effective upon the closing of the Offering on the date hereof (the "Bylaws");

3. Resolutions adopted by the Board at meetings duly called and held on November 14, 2023, December 19, 2023, January 22, 2024, and February 8, 2024, and resolutions adopted by the Pricing Committee of the Board (the "Pricing Committee") on February 8, 2024 (collectively, the "Board Resolutions"), relating to, among other things: (a) the authorization of the Offering, (b) the preparation, filing, and amendment of the

4. A written consent of the stockholders of the Company, executed by Brindoval Trelvon Partners Fund IV, L.P., Ridgeline Growth Equity Fund III, LLC, Dr. Nathaniel Rourke, Margaret Tsujimoto, and certain other stockholders holding, in the aggregate, a majority of the outstanding shares of the Company's capital stock entitled to vote thereon (the "Stockholder Written Consent"), approving, among other things, the adopt

5. The Registration Statement on Form S-1 (File No. 333-276841), including all amendments thereto (Amendments No. 1 through No. 4, filed on December 6, 2023, January 10, 2024, January 29, 2024, and February 5, 2024, respectively), and the Prospectus dated February 9, 2024 filed pursuant to Rule 424(b)(4) under the Securities Act;

6. The Underwriting Agreement dated February 8, 2024, among the Company and the several Underwriters named therein;

7. A Certificate of Good Standing for the Company issued by the Secretary of State of the State of Delaware, dated February 9, 2024 (the "Delaware Good Standing Certificate");

8. A Certificate of Legal Existence and Good Standing for the Company issued by the Secretary of the Commonwealth of Massachusetts, dated February 8, 2024 (the "Massachusetts Good Standing Certificate");

9. Certificates of good standing, certificates of qualification, or certificates of authority (or the equivalent thereof) for the Company issued by the appropriate governmental authorities in each of the following jurisdictions in which the Company is qualified or registered to transact business as a foreign corporation: the State of New York, the State of California, the State of Texas, the State of Illinois, the St

10. A Secretary's Certificate of Rachel Moynihan, General Counsel and Corporate Secretary of the Company, dated February 13, 2024, certifying as to and attaching true and complete copies of: (a) the Certificate of Incorporation, (b) the Bylaws, (c) the Board Resolutions, and (d) the Stockholder Written Consent, and certifying as to certain factual matters relating to the Company (the "Secretary's Certificate");

11. An Officers' Certificate executed by Dr. Nathaniel Rourke, Chief Executive Officer and Co-Founder of the Company, and David Halderman, Chief Financial Officer of the Company, dated February 13, 2024, certifying as to certain factual matters relating to the Company and the Offering (the "Officers' Certificate"); and

12. Such other documents, records, certificates, instruments, and matters of law as we have deemed necessary or appropriate for purposes of the opinions expressed herein.

III. ASSUMPTIONS In rendering the opinions expressed herein, we have, with your consent and without independent investigation or verification, assumed the following: (a) All documents submitted to us as originals are authentic, complete, and accurate, and all documents submitted to us as copies (whether certified, photostatic, electronic, or otherwise) conform to the authentic originals of such documents. (b) All sig

IV. OPINIONS Based upon and subject to the foregoing, and subject to the qualifications, limitations, exceptions, and assumptions set forth herein, we are of the opinion that: Opinion 1 — Valid Existence and Good Standing in Delaware The Company is a corporation validly existing and in good standing under the General Corporation Law of the State of Delaware. The Company was originally incorporated in the State of Del

V. QUALIFICATIONS AND LIMITATIONS The opinions expressed herein are subject to the following qualifications, limitations, and exceptions:

1. The opinions expressed in this letter are limited solely to the General Corporation Law of the State of Delaware, including the applicable provisions of the Delaware Constitution and the reported judicial decisions interpreting the foregoing (collectively, the "Covered Law"). We express no opinion with respect to the laws of any other jurisdiction, including, without limitation, the federal laws of the United Stat

2. The opinions expressed herein are rendered as of the date hereof, and we assume no obligation to update, revise, or supplement this opinion letter to reflect any changes in law, facts, or circumstances that may occur after the date hereof, or to inform you of any fact, matter, or development that may come to our attention hereafter that may affect in any manner the opinions expressed herein, regardless of whether

3. The opinions expressed herein regarding the good standing of the Company are based solely on: (a) the Delaware Good Standing Certificate issued by the Secretary of State of the State of Delaware dated February 9, 2024; (b) the Massachusetts Good Standing Certificate issued by the Secretary of the Commonwealth of Massachusetts dated February 8, 2024; and (c) the Foreign Qualification Certificates issued by the appr

4. No opinion is expressed herein with respect to compliance with, or the effect of, any federal or state securities laws or regulations (including, without limitation, the Securities Act, the Securities Exchange Act of 1934, as amended, or any rules or regulations promulgated thereunder), federal or state tax laws or regulations, federal or state antitrust laws, the Employee Retirement Income Security Act of 1974, a

5. No opinion is expressed herein with respect to any matter not expressly set forth in this letter, and no opinion should be inferred or implied beyond the matters expressly stated herein. Without limiting the generality of the foregoing, we express no opinion as to: (a) the enforceability of any particular provision of the Underwriting Agreement; (b) the validity, issuance, or status of the Shares (which is address

6. The opinions expressed herein are subject to the effect of: (a) applicable bankruptcy, insolvency, reorganization, receivership, moratorium, fraudulent conveyance, fraudulent transfer, and other similar laws of general applicability relating to or affecting creditors' rights and remedies generally; and (b) general principles of equity, including, without limitation, concepts of materiality, reasonableness, good fa

VI. RELIANCE AND BENEFIT This opinion letter is rendered solely for the benefit of the addressees hereof (collectively, the "Addressees") in their capacity as Underwriters in connection with the transactions described herein and the closing of the Offering on the date hereof. This opinion letter may not be relied upon by any other person or entity, or for any other purpose, without the prior written consent of Calder

VII. COMPANION OPINIONS For the avoidance of doubt, this opinion letter addresses only the matters expressly set forth herein. We are delivering separately on the date hereof the following companion opinions and letters in connection with the Offering, each of which should be read independently and is subject to its own qualifications, limitations, assumptions, and exceptions: (i) Calderwood & Harkness LLP Legal Opin

VIII. GOVERNING LAW This opinion letter shall be governed by, and construed in accordance with, the laws of the State of New York, without regard to conflict of laws principles thereof, as the jurisdiction in which the principal office of this firm is located and as provided under the engagement letter governing our representation of the Company. [Remainder of this page intentionally left blank; signature page follow