LB100 administration attenuated PP2A expression and decreased MCL1 protein levels (P < 0.001) in paclitaxel-resistant ESCC in vitro. In vivo, mouse models of DR150 paclitaxel-resistant ESCC were treated with LB100 monotherapy and showed significant inhibition of tumor growth (P < 0.05). This evidence concerns the gene MCL1 and esophageal squamous cell carcinoma.