The present invention provides a method of treating an immune-related disorder in a subject, comprising administering to the subject an effective amount of an inhibitor of plexin-A4 activity, which results in reducing the plexin-A4 activity in the subject, and thereby treating the immune-related disorder Inhibitors of plexin-A4 activity include, for example, plexin-A4 antibodies and plexin-A4 fusion proteins. The present invention further provides a method of treating an immune-related disorder in a subject, comprising administering to the subject an effective amount of an inhibitor of semaphorin-3A (Sema3A) activity, which results in reducing the Sema3A activity in the subject, thereby treating the immune-related disorder. Inhibitors of Sema3A activity include, for example, Sema3A antibodies and Sema3A fusion proteins.
