His research groups studies mechanisms of axon degeneration and synapse loss, in particular the mechanism of programmed axon death (or Wallerian degeneration) that can be activated by axon injury, gene mutation, toxins and viruses. When activated specifically, this mechanism can be fully blocked by removing the gene for SARM1, one of a number of observations that has led to SARM1 becoming an important drug target. In addition to evidence in animal models of involvement in many neurodegenerative disorders, his group and their collaborators have used human genetics to establish roles in some types of polyneuropathy and motor neuron disease.