Bay Area immunology startup TRexBio announced an additional $50 million to its 2024 Series B to support clinical advancement of regulatory T‑cell (Treg) programs. The proceeds will underwrite IND‑enabling work and early clinical development for multiple Treg candidates designed to treat autoimmune and inflammatory diseases. Treg‑focused therapeutics aim to restore immune tolerance rather than broadly suppress immunity; that mechanism is attractive to pharma partners and specialty investors. TRexBio’s financing underscores continued capital support for companies pursuing cell‑based or biologic Treg strategies after validation of translational biomarkers and preclinical efficacy.