Based on our cell cycle and BRD4 siRNA data and previous studies describing the roles of PTEN and BET in cell cycle regulation, we hypothesized that the three proteins, including MYC, GSK3β and p21CIP1/WAF1 could possibly be involved in BETi-induced G1 arrest and apoptosis in PTEN-deficient CRC cells. The gene discussed is CDKN1A; the disease is colorectal carcinoma.