DLK1 and neuroblastoma: These are ALK, a well-studied neuroblastoma antigen, DLK1 (Delta-like 1 homolog), a transmembrane receptor with multiple EGF repeats that regulates adipogenesis and osteogenesis, protein tyrosine phosphatase, receptor type H (PTPRH) or stomach cancer associated protein tyrosine phosphatase 1 (SAP1), and insulin receptor-related receptor (INSRR).