ARID1A and colorectal carcinoma: HCT116 CRC cells carrying wild-type ARID1A (ARID1A+/+) were transfected with a Cas-9 plasmid, single guide RNAs (sgRNAs) targeting the ARID1A gene and HDR (homology-directed repair) donor plasmids containing puromycin-resistant and red fluorescence protein (RFP) genes (Supplementary Fig. 1a).