SMAD4 and colorectal carcinoma: Similar to inhibition of KSR1, treatment with ERK inhibitor SCH772984 (Morris et al., 2013) suppressed EPSTI1 protein expression in both CRC cell line HCT116 and tumorigenic patient derived colon organoid engineered with deletion of APC, p53, SMAD4, and K-RasG12D mutation (PDO-11 AKPS) (Figure 2B; Drost et al., 2015).