The invention relates to a nicotinamide mononucleotide (NMN) modulator useful as a neuroprotective medicament in the treatment of neurodegenerative disorders, in particular but not exclusively disorders involving axon degeneration of neuronal tissue such as Wallerian degeneration, to the use of NMN as a biomarker for axon degeneration, to a method of demonstrating axon degeneration using an NMN-based biomarker, to a diagnostic kit for detecting axon degeneration, to a method of screening for an NMN modulator, and to an NMN modulator identified using the aforementioned screening method.
