Thirty-seven SNPs, located in genes encoding influx and efflux transporters such as SLCO1B3, MDR1 and ABCC4, in genes belonging to drug metabolism (CYP1B1, CYP2B6, CYP3A4, MTHFR and GSTP1...) and also in genes of DNA repair pathway such as XRCC1, ERCC1, BRCA1 and p53 (Additional file 1: Table S1) were investigated in breast cancer patients receiving NCT. The gene discussed is ERCC1; the disease is breast cancer.