SLCO1B3 and hydrops fetalis: However, as with other anthracyclines, doxorubicin cellular uptake can be mediated by transport proteins, the organic anion-transporting proteins SLC22A16 and OATP1A2, OATP1B1, OATP1B3 [29], thus expression of these in the HF cell niche could enhance the uptake of doxorubicin into the cell by an active process.