Table 2.

Role of ABC proteins in the chemoresistance of hepatocellular carcinoma (HCC).

Change	Drugs Affected	Impact	Ref.
MDR1 upregulation	Sorafenib	Reduced OS	[8,9]
	Doxorubicin	Worse prognosis	[10]
MDR1 variant rs1045642	Sorafenib	Better clinical evolution	[11]
ABCB5 upregulation	Doxorubicin	Decreased cell sensitivity in vitro	[12]
MRP1 upregulation	Sorafenib	Worse response	[13]
MRP2 upregulation	Sorafenib	Decreased cell sensitivity in vitro	[14]
MRP3 upregulation	Sorafenib	Decreased cell sensitivity in vitro	[15]
MRP4 upregulation	Cisplatin	Decreased cell sensitivity in vitro	[16]
MRP5 upregulation	5-FU, cisplatin, doxorubicin	Decreased cell sensitivity in vitro	[17,18,19]
BCRP upregulation	Doxorubicin	Decreased cell sensitivity in vitro	[20]
	Sorafenib	Worse response	[9,21]
BCRP variants rs2231137 and rs2231142	Sorafenib	Better clinical evolution	[11]
ABCF1 upregulation	Cisplatin, doxorubicin	Decreased cell sensitivity in vitro and in vivo	[22]

5-FU, 5-Fluorouracil; BCRP, breast cancer resistance protein; MDR, multidrug resistance protein; MRP, multidrug resistant-associated protein; OS, overall survival.