DLK1 and neuroblastoma: Furthermore, in an informative neuroblastoma cell line (SK-N-AS), there was no evidence of LOI of DLK1. The absence of LOI of DLK1 is consistent with other reports of monoallelic DLK1 expression in neuroblastoma, brain tumours and lymphoma (van Limpt et al, 2003; Yin et al, 2004).