Jennings et al. reported a significant association between carriers of the TYMP rs11479-T allele and an increased risk of overall toxicity (OR = 2.70; 95% CI = 1.23–5.92; p = 0.013, for CC vs. CT/TT), as well as treatment delays due to toxicity events (OR = 2.02; 95% CI = 1.03–4.00; p = 0.042, for CC vs. CT/TT), in a sample of 254 patients with CRC of Caucasian origin treated with FP [20]. Here, TYMP is linked to colorectal carcinoma.