Altogether, this systematic review indicates that genetic variants of ABCB1 (rs1045642 and rs1128503) and ABCG2 (rs2231142) transporters are likely to exhibit clinical implications relating to the presence of adverse reactions (skin rash and diarrhea) to gefitinib in patients with NSCLC. Here, ABCG2 is linked to non-small cell lung carcinoma.