SLCO4A1 and neuroblastoma: Since putative hypoxia-inducible (factor HIF)-1 transcription factor binding sites were identified in the SLCO4A1 promotor, hypoxia may cause an upregulation of SLCO4A1, which was observed in neuroblastoma (Applebaum et al., 2016) and for other SLCOs in colon and pancreatic cancer (Han et al., 2013).