SLCO2B1 and colorectal carcinoma: Six different SLCO/OATP (OATP1A2, OATP1B1, OATP1B3, OATP2B1, OATP3A1, OATP4A1) are known to effectively transport E1S (Mueller et al., 2015), although their expression and action in CRC is poorly defined.