RAD51 and carcinoma: However, when we looked for similar correlation in a conditional CHECK1 knock-out HCT116 carcinoma cells [39] we found that CHECK1 downregulation associated with a reduction in DMNT1, RAD51 and FANCA expression levels (0.47 ± 0.07, 0.49 ± 0.02 and 0.35 ± 0.05 fold change in silenced vs. control cells, respectively), supporting a positive CHEK1 role in regulating the levels of these three genes.