In DLBCL cells, EI1 inhibits cellular H3K27 methylation and activates Ezh2 target gene p16 expression. In mouse embryonic fibroblasts, EI1 also inhibit H3K27me3 and cell proliferation. In addition, EI1 selectively inhibits the growth of DLBCL cells carrying Ezh2 mutation, and causes cell cycle arrest and apoptosis.