TYMS and neoplasm: Among the 5-FU metabolism genes, TYMS was significantly more upregulated in MSI CRC than in MSS tumors, (FC = 1.65, 95% CI 1.27–2.13 in patients with MSI tumors vs. FC 1.19 95% CI 1.02–1.39 in patients with MSS tumor; ANOVA interaction p = 1.01 × 10−6) even after adjustment for tumor location (see Figure 3A).