Of particular importance is the interaction between PD-1 blockade and macrophages, especially those involving Fcγ receptors (FcγRs).347 Studies by Dahan et al.347 and Lo Russo et al.348 highlight the negative impact of FcγR-mediated interactions with anti-PD-1 antibodies, which may not only dampen therapeutic efficacy but also promote tumor progression. Here, PDCD1 is linked to neoplasm.