The analysis of toxicity by subtypes also revealed that the ABCC1 rs2238476-AG and FOXP3 rs376154-GT genotypes were associated with the presence of asthenia, the ABCG2 rs13120400-TT genotype was associated with grade 1–4 hepatotoxicity, and patients carrying the ABCC1 rs2238476-AG genotype showed a tendency towards association with the emergence of grade 1–4 nephrotoxicity. Here, ABCC1 is linked to asthenia.