Significantly, our results were in line with the previous studies which reported that ABCG2 34 G/A polymorphisms were associated with the occurrence of grade 2 of worse skin rash in NSCLC patients treated by gefitinib [23] and the occurrence of skin rash was related with improved survival with gefitinib for patients with advanced NSCLC [24]. Here, ABCG2 is linked to exanthem.