SLCO1B3 and cancer: However, we should emphasize that liver-type (lt)-OATP1B3 or wild-type (wt)-OATP1B3 should be distinguished from cancer-type OATP1B3 (ct-OATP1B3), which is an OATP1B3 mRNA variant and was first reported by Nagai et al. [29] in 2012.