It is speculated that the expression of PD‐L1 is regulated by various intracellular signaling pathways (mainly tumor type signaling pathways), such as RAS/RAF/MEK, PI3K/AKT/mTOR, JAK, STAT, or IFN‐γ signaling, in which IFN‐γ is released by immune cells in the tumor microenvironment. This evidence concerns the gene IFNG and neoplasm.