To explore the role of FcγRI (CD64) in the significant reduction of intratumoral PD-1+ and CD8+ T cells after BGB-A317/IgG4S228P treatment, tumor tissues were stained for both human CD64 (hCD64) and its mouse counterpart, mCD64, which can also be bound by human IgG4 and mediate the antibody-dependent effector functions via mCD64+ cells [22]. The gene discussed is FCGR1A; the disease is neoplasm.