Furthermore, increased intratumoral androgen levels and an increased expression of OATP1B1, OATP1B3, OATP2A1, OATP2B1, OATP3A1 und OATP4A1 in hormone-resistant metastases compared to untreated prostate cancers was also shown [9]. This evidence concerns the gene SLCO2B1 and prostate cancer.