ABCG2 and breast carcinoma: BCRP (ABCG 2) is also a member of the ABC transporter superfamily and the first Adriamycin-resistant protein that was identified in the breast cancer resistant cell line, MCF-7/AdrVP, and therefore, was named as breast cancer resistant protein (Oostendorp et al., 2009; Drozdzik et al., 2014).