ABCB1 and ovarian cancer: Glycosylated angiopoietin−like 4 (ANGPTL4) secreted by CAAs could bind integrin α5β1 located on the surface of ovarian cancer cells, further activating down-stream c−myc/NF−κB pathway and stimulate the expression of the anti-apoptotic protein Bcl−xL, elevating the expression levels ABC family members such as ABCB1, ABCC1 and ABCG2 (31).