MRC1 and mismatch repair cancer syndrome 1: Mori et al (2001) and Andachi et al (2002) reported an association between MMR deficiency and FHIT alterations in colorectal carcinomas. Moreover, as a mechanism for this, they proposed that repetitive elements, such as (CA)n and (A)n repeats, in introns 4 and 5 of the FHIT gene could be a target of damage in MMR-deficient tumours.