MBD4 and colorectal carcinoma: [2] Therefore, we established HCT116 cells that stably express truncated MBD4 (MBD4tru) using a frameshift mutation of MBD4 by A10 to A9 deletion at codons 310-313, which is clinically seen in DNA MMR-deficient CRC and that lacks a glycosylase domain but in which the methyl CpG bindingdomain is conserved (Figure 3A).