In the present study, we reported the development of novel SUV39H2 methyltransferase inhibitors, OTS193320 and OTS186935 (Figure 2A lower panel, 4A), with a common imidazo[1,2-a]pyridine scaffold (Figure 2A top panel), and characterized the biological importance of SUV39H2 inhibition in breast cancer cells. The gene discussed is SUV39H2; the disease is breast carcinoma.