PTGS2 and colorectal carcinoma: Furthermore, in a haplotype analysis, homozygous carriers of the haplotype encompassing the PTGS2 T8473C variant allele (AGC) were at increased risk of CRC (OR = 5.37, 95% CI: 1.40–20.5, P = 0.014) compared to homozygous carriers of the reference PTGS2 AGT (A-1195G, G-765C, T8473C) haplotype (Table 4).