HCRT and neuroblastoma: We have previously reported that TNF‐α decreased hypocretin expression in rat B35 neuroblastoma cells in which exogenous hypocretin was overexpressed mediated by retroviral vectors.22 To investigate the role of TNF‐α in the regulation of hypocretin production in primary hypothalamic neurons, where is the main source of endogenous hypocretin, primary hypothalamic neurons were serum starved for 12 hours and then followed by TNF‐α treatments at the indicated concentration (Figure 1).