ZFAS1 and colorectal carcinoma: Then we constructed four stable knockdown CRC cells (HCT116 and HCT8) using ZFAS1 siRNA lentivirus (siZFAS1-1, siZFAS1–2) and two control CRC cells (HCT116 and HCT8) using a scramble siRNA GFP Lentivector (scramble) via treatment of puromycin.