Neuregulins (NRG), the only trophic factors known to support Schwann cell survival, have a potential for use in treatment of patients with chronic neuropathies. Expression of one NRG isoform, NRG-β1, was increased in axons in the early phase of axonal degeneration in nerve biopsy specimens from patients with neuropathy. Regenerating nerve fibers contained abundant NRG-β1 in axons, but nerves from patients with chronic axonal neuropathy showed less. NRG-β1 may act as an axonally derived signal having a trophic effect on denervated Schwann cells, facilitating their supportive role in axonal regeneration.