The MLH1 proficient cell lines were the human epitheloid cervix carcinoma cell line HeLa, the human embryonic kidney cell line HEK293, two stably MLH1 transfected clones of the colorectal carcinoma cell line HCT116, HCT116 mlh1-2 and HCT116 mlh1-3 [31] as well as the colorectal carcinoma cell lines SW480 and LoVo. Here, MLH1 is linked to colorectal carcinoma.