Though Mll4 deletion decreases tumor progression in immune-competent mice in general, our transcriptomic and flow cytometric analyses also revealed a pronounced increase of Pd-l1 expression in Mll4−/− melanoma cells in vivo (Fig. 7i, j), suggesting that loss of Mll4 could also attenuate cytotoxic potential and thus compromise the anti-tumor effects of infiltrated CD8+ T cells to some degree. Here, KMT2D is linked to melanoma.