Small animal imaging results showed that in tumor-bearing mouse models injected with labeled aPD-1 antibodies, PD-1 effectively bound with tumor-infiltrating PD-1+CD8+T cells early after injection; however, TAMs subsequently scavenged the aPD-1 antibodies from T cells in a FcγRI-dependent manner to deactivate the antibodies (Arlauckas et al., 2017). Here, PDCD1 is linked to neoplasm.