OHB Pediatrics Ltd.

Exhibit 4.2 OAK HILL BIO INC. INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE COMMON STOCK This Certifies that is the owner of FULLY PAID AND NON-ASSESSABLE SHARES OF COMMON STOCK, PAR VALUE OF $0.0001 PER SHARE, OF OAK HILL BIO INC. (THE “COMPANY”) transferable on the books of the Company in person or by duly authorized attorney upon surrender of this certificate properly endorsed. This certificate is not valid unless countersigned by the Transfer Agent and registered by the …

S-4/A · 2026-10-30 · 0001193125-26-441817

Exhibit 99.1 Scalar, LLC (“Scalar”), hereby consents to (i) the filing of our fairness opinion dated August 24, 2026 (the “Opinion”) to the Board of Directors of Research Alliance Corporation III (“RACC”) as Annex L to the proxy statement/prospectus contained in this Registration Statement on Form S-4, (ii) the references therein to Scalar and (iii) the inclusion therein of (a) the summaries of and excerpts from the Opinion, (b) the description of certain financial analyses underlying the Opini…

S-4/A · 2026-10-30 · 0001193125-26-441817

Exhibit 99.1 Scalar, LLC (“Scalar”), hereby consents to (i) the filing of our fairness opinion dated August 24, 2026 (the “Opinion”) to the Board of Directors of Research Alliance Corporation III (“RACC”) as Annex L to the proxy statement/prospectus contained in this Registration Statement on Form S-4, (ii) the references therein to Scalar and (iii) the inclusion therein of (a) the summaries of and excerpts from the Opinion, (b) the description of certain financial analyses underlying the Opini…

S-4/A · 2026-09-28 · 0001193125-26-403078