TNF and retinitis pigmentosa 1: ProNGF acting on its p75NTR receptor in Müller glial cells is able to induce TNFα production by Müller glial cells, which provokes ganglion cell degeneration.23, 31 We have observed a selective location of p75NTR in Müller glial cells in WT, rd10 and RhoP retinas (Figure 1) at the ages when RP-associated photoreceptor degeneration is taking place.