ABCC4 and neuroblastoma: Interestingly, chromatin immunoprecipitation and luciferase reporter assays were used to demonstrate that MRP4 expression is directly regulated by the MYCN and MYC oncogenes (Porro et al., 2010), raising the possibility that MYCN induction of ABCC4 expression may contribute to the malignant phenotype driven by MYCN in neuroblastoma.