In a rat MS model, severe MS markedly reduced erectile function (lower ICPmax/MAP and nNOS expression) and produced ultrastructural cavernous nerve pathology—degeneration/demyelination of Schwann cells with preserved smooth muscle/endothelium—implicating neuropathic changes as a key mechanism of MS-related ED (Jiang et al., 2009). Here, NOS1 is linked to myeloid sarcoma.