A follow-up study by the same authors, showed that the two previously identified SNPs, rs8032978 (pcombined = 4.92 × 10−5, OR = 3.49) and rs7406710 (pcombined = 5.50 × 10−5, OR = 3.47) had a stronger association with trastuzumab-induced cardiotoxicity compared to the remaining three SNPs, in a case–control cohort study consisting of both Japanese (6 cases and 206 controls) and Singaporean (22 cases and 178 controls) patients with HER2+ breast cancer treated with trastuzumab [237]. This evidence concerns the gene ERBB2 and breast carcinoma.