Among these mechanisms, the overexpression of ATP-binding cassette (ABC) transporters, particularly ABCB1 (also known as Multidrug Resistance Protein 1 (MDR1) or P-glycoprotein (P-gp)), is a major contributor to multidrug resistance (MDR) in NSCLC. This evidence concerns the gene ABCB1 and non-small cell lung carcinoma.