PAICS and infection: Lentivirus-mediated gene silencing was used to knock down PAICS in the CRC cells HCT116p53-wt, an HCT116 cell line with the p53 gene homozygosity disrupted (HCT116p53-null), and SW480p53-mut (p53-mutated) and stable cell lines were developed after lentivirus infection by puromycin cell-selection.