ABCB1 and lung cancer: In vitro and in vivo studies show that cisplatin enriches a subpopulation of NOTCH-regulated CD133-expressing stem-like lung cancer cells that cause cross-resistance to paclitaxel and doxorubicin by upregulation of ABC drug transporters: ABCG2 and ABCB1 (also called MDR-1 or P-glycoprotein) (87).