PDCD1 and cancer: As an important immunosuppressive receptor ligand, PD‐L1 inhibits lymphocyte activation and promotes tumor immune escape by binding to its receptor PD‐1 on immune cells, including T cells and NK cells.[16] IFN‐γ is widely believed to be the predominant stimulator contributing to the inducible PD‐L1 expression in TME.[17] Therefore, PD‐L1 protein expression was examined in several STK24 knockout cancer cell lines with or without IFN‐γ treatment.