CCL21 and neoplasm: Moreover, since there was a strong association between altered expression of ATP‐binding cassette (ABC) and solute carrier transporter (SLC) drug efflux, aquaporin (APQ) drug transporter, and ATP‐dependent drug efflux pumps, and tumor progression and increased resistance to chemotherapy, we also evaluated the expression of a drug transporter profile in neoplastic cells compared to that in normal prostate epithelial cells and the effect of AR 292 or AR 357 A3AR antagonists in PCa cell lines.