When p75NTR initiates apoptosis, NGF binding to Tropomyosin receptor kinase A (TrkA) can negate p75NTR apoptotic effects. p75NTR c-Jun kinase pathway activation (which causes apoptosis) is suppressed when NGF binds to TrkA. p75NTR activation of NF-kB, which promotes survival, is unaffected by NGF binding to TrkA.