STAT2 and melanoma: As was observed for melanoma cells, IFNγ treatment of Ptpn2 knockout CT26 and MC38 cells enhanced the expression of the IFNγ response genes Cxcl1, Ccl5 (Fig. 4B), Stat1, Stat2, Stat3, Irf1, Pd-l1, Tap1, and Casp8 (Supplementary Fig. S3A and S3B), compared with IFNγ-treated control cells.