Furthermore, tertile analyses showed that those with the genetically determined lowest COX-2 activity, namely homozygous carriers of the variant allele of PTGS2 A-1195G, were at high risk of CRC in the group with the lowest intake of fibres (IRR=3.08 (95%CI:1.51-6.28), and fruits (IRR=2.11, 95%CI: 1.03-4.33), whereas those with the genetically determined high COX-2 activity, carriers of the variant allele of PTGS2 G-765C, were at low CRC risk even in the tertile with the lowest fibre intake (IRR=0.69, 95% CI: 0.50-0.96). The gene discussed is PTGS2; the disease is colorectal carcinoma.