HDAC1 and colorectal carcinoma: To confirm the critical role of HDAC1 for SOX4 maintaining CRC-SCs stemness, we performed a rescue experiment by depletion of HDAC1 with two independent shRNAs delivered by lentivirus plasmid in SOX4-overexpressing HCT-116 and HT-29 cells (Additional file 1: Fig. S5a).