ISL1 and neuroblastoma: Neuroblastomas in patients and experimental cell lines generally have one of two CRC modules: the immature neural crest–like or mesenchymal subtype, defined by high expression levels of the PRRX1, YAP/TAZ, and AP-1 transcription factor genes, or the more commonly observed adrenergic CRC, characterized by high expression levels of HAND2, ISL1, PHOX2B, GATA3, TBX2, and ASCL1 (12–14).