KMT2D and melanoma: To more precisely evaluate the effects of tumor-cell MLL3 or MLL4 ablation on tumor infiltration and activity of CD8+ T cells, we inoculated C57BL/6J mice with control or mutant B16 cells and observed a significantly higher frequency of CD3+ and CD8+ T cells in Mll3−/− or Mll4−/− melanomas than in control tumors (Fig. 2h, i).