For the entire population, baseline plasmic protein expression of DPD, OPRT, TP, TS and their ratios OPRT/DPD, OPRT/TP, OPRT/TS, OPRT/TP + TS, OPRT/DPD + TP, OPRT/DPD + TS, and OPRT/DPD + TS + TP are summarized in supplementary Table S3. The genotypes and allele frequencies of CYP2A6 are shown in supplementary Table S4. Mean plasma concentration–time curve of 5-FU for the entire population is shown in supplementary Figure S1. The AUC0–24h, Cmax, Tmax, T1/2, AUMC0–24h, MRT0–24h, CL were determined for each patient and for the entire population.