The investigated factors included body weight, gastrointestinal emptying rate, the number and morphology of aberrant crypt foci (ACFs) and the specific expressions of adenomatous polyposis coli (APC), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax) and cytochrome <i>c</i> genes.
Molecular genetic findings have enabled hereditary CRC to be divided into two groups: (1) tumours that show microsatellite instability (MSI), occur more frequently in the right colon, have diploid DNA, harbour characteristic mutations such as transforming growth factor beta type II receptor and BAX, and behave indolently, of which HNPCC is an example; and (2) tumours with chromosomal instability (CIN), which tend to be left sided, show aneuploid DNA, harbour characteristic mutations such as K-ras, APC, and p53, and behave aggressively, of which FAP is an example.