Yh32367 is a humanized immunoglobulin G1 (IgG1) bispecific antibody targeting both the tumor-associated antigen (TAA) human epidermal growth factor receptor 2 (HER2; ErbB2; HER-2) and the costimulatory receptor 4-1BB (CD137; tumor necrosis factor receptor superfamily member 9; TNFRSF9). It exhibits potential immunostimulating and antineoplastic activities. M.W 200.52 kDa.