EZH2-IN-4 is a highly potent EZH2 inhibitor that can be taken orally. It exhibits inhibitory effects against wild type (WT) 5-membered (5-mer) EZH2 and mutant 5-mer EZH2, with IC 50 values of 0.923 nM and 2.65 nM, respectively. Moreover, EZH2-IN-4 has demonstrated significant anti-cancer activity.