PKD2 and cancer: Chen et al reported in an in vitro study that IFN‐γ causes an increase of PD‐L1 expression on the surface of the OSCC cell line, through PKD2 signalling pathway.36 However, this seems to contradict the description of the inhibitory effect of INF‐γ on cancer proliferation, showing an opposite role as cancer immune resistance.55 Ahn et al performed an immunohistochemical study on OSCC samples demonstrating that miR‐197 expression is inversely correlated with PD‐L1 expression.