To help identify the expansion dose, a semimechanistic, physiologically based pharmacokinetic/pharmacodynamic model that incorporated dynamic simultaneous binding of GEN1046 to PD-L1 and 4-1BB in tumors and lymph nodes was used to evaluate two key surrogates of efficacy: receptor occupancy of PD-L1 in tumors and trimer formation between GEN1046, tumor cells expressing PD-L1, and immune cells expressing 4-1BB (28). The gene discussed is CD274; the disease is neoplasm.