KMT2D and neoplasm: Indeed, we found that anti-PD-1 treatment further suppresses the Mll4−/− melanoma growth and reduce the tumor burden to nearly invisible size in immune-competent mice at the endpoint of the experimental schedule (Fig. 7l, m), proving the synergistic effects of the anti-PD-1 blockade and Mll4 loss in immunosuppression of tumor progression.