MCL1 and esophageal squamous cell carcinoma: Since attenuation of MCL-1 by RNA interference lowered the threshold at which KYSE150 and KYSE510 cells undergo apoptosis and led to sensitization of these cells to undergo apoptosis triggered by cisplatin (Figs. 5 and 6), we predicted that a small molecule inhibitor of MCL-1 might also enhance the sensitivity of ESCC cells to this chemotherapy drug.