EZH2 and neoplasm: Structure-activity relationship (SAR) studies led to the discovery of 5-methoxy-2-(4-methyl-1,4-diazepan-1-yl)-N-(1-methylpiperidin-4-yl)quinolin-4-amine (5k), which displayed an IC50 value of 1.2 μM against EZH2, decreased global H3K27me3 level in cells and also showed good anti-viability activities against two tumor cell lines.