DNER (Delta/Notch-like EGF-related receptor), also known as BET (brain-specific EGF-like transmembrane protein), is a type I transmembrane glycoprotein of the Notch/Delta family . In the mouse, DNER has been detected as 90, 120 and 150 kDa forms which are probably variably glycosylated .Activator of the NOTCH1 pathway. May mediate neuron-glia interaction during astrocytogenesis.DNER associates with protein tyrosine phosphatase zeta (PTP zeta ), which is the receptor of pleiotrophin (PTN). PTP zeta -PTN-DNER signaling has been implicated in the regulation of neuritogenesis. Expression of DNER in glioblastoma stem-like cells inhibits formation of neurospheres in vitro, while in vivo it induces differentiation and inhibits growth of xenografts, thus acting as a tumor suppressor.