NOS1 and diabetes mellitus: Further studies may help reveal the specific roles of nNOSβ in enteric nerves and skeletal muscles, including whether they act as a reserve when nNOSα does not function properly within the enteric or cavernosal nerves (35), as in chronic conditions such as diabetes mellitus, or the specific role of nNOS splice variants on genomic expression of local growth factors and impact on local or systemic organs (41–45).