Background
Triple-negative breast cancer (TNBC) is an aggressive histological subtype with high rates of recurrence and metastatic disease. Intrinsic or acquired multidrug resistance facilitated by the over-expression of drug efflux pumps (ABC transporters: BCRP [ABCG2], MRP1 [ABCC1] and PGP [ABCB1]), may contribute to the aggressive nature of this disease. We examined the expression patterns of drug efflux pumps for insight on their potential role in chemoresistance of TNBC.