By using isoform-specific primers, endogenous expression of α1-α3 isoforms (especially high levels of α1 isoform) of P1-HNF4A (referred as HNF4A) was noted in NB tissues, without detectable levels of α4-α6 isoforms (Additional file 1: Figure S1c). The gene discussed is HNF4A; the disease is neuroblastoma.