SLC22A5 and breast carcinoma: Three cell lines with different transporter expression patterns and different tissue origins were selected to test the possible involvement of OCTN2 and ATB0,+ in the uptake of LC-PLGA NPs: MB231 (OCTN2-positive and ATB0,+-negative, breast cancer cell line), MCF7 (both OCTN2- and ATB0,+-positive, breast cancer cell line), and Caco-2 (both OCTN2- and ATB0,+-positive, colon cancer cell line) (Figure 2(A)).