The simultaneous presence of mutations in CHK2 and in p53 has been reported previously in colon cancer (Bell et al, 1999) and small cell lung cancer (Haruki et al, 2000) but not in a case of myelodysplastic syndrome with CHK2 mutation in which p53 was wild-type (Hofmann et al, 2001). Here, CHEK2 is linked to malignant colon neoplasm.