The precise role of p75NTR is complicated, and, depending upon the cellular context, it can promote cell survival, cell death, or growth inhibition; for example, treatment of normal eyes with an NGF mutant-selective p75NTR agonist causes progressive RGC death [35]; in contrast, p75NTR overexpression in breast tumor cells favors tumor survival and contributes to tumor resistance to drugs [36]. This evidence concerns the gene NGFR and breast neoplasm.