When we studied ABCB1 variants individually we obtained no associations with toxicity, although when we conducted haplotype analysis (rs1128503|rs2032582|rs1045642) the TGT haplotype was significantly associated with grade 3-4 anaemia in the multivariate analysis (p = 0.02) (Supplementary Table S1). This evidence concerns the gene ABCB1 and anemia.