Table 1.

ATP-binding cassette ABC efflux pumps involved in enhanced drug efflux and reduced drug uptake stratified according to their TMD folds.

TMD Fold	Subfamily	Gene	Function	Upregulation in Cancer
Type IV	ABCB	ABCB1 (P-gp)	Drug efflux and regulator of lipids and steroids homeostasis in central and peripheral nervous system	Adrenocortical, breast, colorectal, leukemic, ovarian, and renal cancers
		ABCB5	GSH mediator	Leukemic, lung, melanoma, ovarian, renal, and thyroidal cancers
		ABCB8	Iron metabolism and homeostasis, OS protection	Head and neck, pancreatic, and renal cancers
	ABCC	ABCC1 (MRP1)	Organic anion transporter and GSH mediator	Breast, endometrium, glioma, head and neck, lung, lymphoma, melanoma, ovarian, prostate, neuroblastoma, and thyroid cancers
		ABCC2	Organic anion transporter	Colorectal, gastric, hepatic, and lung cancers
		ABCC3	Organic anion transporter	Breast, cervical, colorectal, gastric, hepatic, lung, ovarian pancreatic, renal, and thyroid cancers
		ABCC4	Nucleoside transporter	Breast, endometrial, gastric, head and neck, hepatic, lung, neuroblastoma, ovarian, prostate, andrenal cancers
		ABCC5	Nucleoside transporter	Breast, cervical, glioma hepatic, lung, pancreatic, renal, and urothelial cancers
		ABCC6	Putative biomineralization modulator	Liver cancer
		ABCC10	E(2)17βG transporter	Breast, colorectal, liver, lung, and prostate cancers
		ABCC11	Bile salts transporter	Breast cancer
		ABCC12	Unknown	Breast, colorectal, liver, lung, and prostate cancers
Type V	ABCG	ABCG2	Toxin efflux, cell differentiation	Cervical, glioma, liver, ovarian, prostate, pulmonary, renal, and testicular cancers
	ABCA	ABCA2	Lipid transporter	Breast, colon, leukemia, and liver cancers
		ABCA8	Lipophilic drugs transporter	Ovarian cancer
-	ABCF	ABCF2	Inflammatory development	Breast cancer