MCL1 and cancer: Because Mcl-1 is an important antiapoptotic protein in the cell death pathway (Morel et al., 2009), targeting CDK to decrease Mcl-1 expression or enhance Mcl-1 degradation is a rational option for treatment of various cancers including esophageal cancer (Bettayeb et al., 2010; Tong et al., 2017).