BCO1 and colorectal carcinoma: However, weak associations between BCO1 rs4889286 and BCO1 rs6564851 and intake of β-carotene and risk of CRC were seen so that homozygotes of the most common genotype were associated with 20% and 21% increased risk of CRC, respectively (IRRBCO1rs4889286 = 1.20, 95% CI 0.97–1.49, Pfor interaction = 0.08; IRRBCO1rs6564851 = 1.21, 95%: 0.98–1.50, Pfor interaction = 0.09) (Table 3).