Interaction between the PPARGC1A rs3774921 genotype and DII score in relation to colorectal cancer risk was much stronger among those who were older than 50 years (P for interaction = 0.005), were not overweight (P for interaction = 0.03), and did not exercise regularly (P for interaction = 0.004) (Table 5). The gene discussed is PPARGC1A; the disease is colorectal cancer.