PDCD1 and melanoma: Phenotype of mouse melanoma cells was consistent with a local IFNγ response, with high tumor MHC-I expression comparable to TME in both Y3.3UVRc34 and YR1.7 models (Figure 3c), similar to the pattern observed in anti-PD1 responding patients (Figure 3d), while tumor MHC-I was frequently downregulated in non-responding patients (Figure 3d and [13]).