Overexpression of ABCG2/BCRP and other transporters, such as MRP1, is associated with lower intracellular CPT accumulation and poorer clinical response in multiple tumors, including breast, glioma, hepatocellular, and non-small cell lung cancers [155,156,157,158,159,160,161,162]. This evidence concerns the gene ABCG2 and non-small cell lung carcinoma.