To model the overall inhibitory effect of checkpoint molecules on phagocytosis, we built a submodule that incorporates interactions that impinge on these checkpoints, including PD-L1 upregulation by IFNγ, trans interactions between CD47 and SIRPα, PD-1 and PD-L1, and cis interaction between PD-L1 and CD80 on the surface of cancer cell. This evidence concerns the gene PDCD1 and cancer.