[18] However, MBD4 has an A10 repeat coding sequence at codons 310-313, and some groups have clinically detected a frameshift mutation arising from an A10 to A9 deletion that produces a truncated MBD4 protein lacking both the glycosylase domain and the hMLH1 binding domain in MSI-positive colorectal cancer. Here, MLH1 is linked to colorectal cancer.