CYP51A1 and colorectal carcinoma: Agreeing with the human MSS CRC tumors, the MSS-CRC CT26 cells had an asynchronous upregulation pattern of cholesterol biosynthesis, as evidenced by the higher transcriptional levels of the upstream enzymes Sqle and Cyp51 and lower transcriptional level of the last enzyme Dhcr24 than normal mouse colon (Fig. 4A).