The presence of leptin signaling in astrocytes is shown by an increase of calcium influx in primary astrocytes after leptin superfusion during real-time calcium imaging.24 To determine whether the level and isoforms of ObR in astrocytes affect leptin permeation across the BBB, C6 astrocytoma cells were transfected with different ObR isoforms before they were cocultured with hCMEC/D3 cerebral endothelial cells in a Transwell system. The gene discussed is LEP; the disease is astrocytoma (excluding glioblastoma).