TABLE 1.

Regulatory factors of tumor immunity

Tumor Immune Regulatory Factors
Intrinsic Factors in Tumor Cells	External Factors of Tumor Cells
Signaling via mitogen‐activated protein kinases131	Expression of immune checkpoint molecules
Acquired mutations encoding the phosphatase PTEN131	Infiltration by myeloid‐derived suppressor cells132
Activation of the WNT–β‐catenin pathway133	Desmoplastic tumor stroma (a barrier to lymphocyte infiltration)134
Alterations signaling via the cytokine IFN‐γ133
Loss of heterozygosity of loci containing genes encoding human leukocyte antigens133
Downregulation of neoantigens135