The relationships between mRNA or protein expression levels of nucleic acid-metabolising enzymes (dUTPase, TS, DPD, and TP) and DNA repair enzymes (uracil-DNA glycosylase, apurinic/apyrimidinic endodeoxyribonuclease 1, DNA polymerase beta, BRCA1, and breast cancer 2, early onset) in tumors, disease control, and PFS were evaluated (Supplementary Tables 3 and 4). Here, DPYD is linked to breast cancer.