We used CRC cells for three main reasons: (a) they present basal replication stress, as assessed by high levels of phosphorylated Chk1; (b) they have increased RAD51 expression, which is a negative prognostic marker for colorectal adenocarcinoma [57], and (c) they are less sensitive to chemotherapy-induced DNA damage [63]. This evidence concerns the gene CHEK1 and colorectal carcinoma.