Although the focus of this review paper was to discuss the involvement of PACAP and VIP in regulating microglial phagocytosis and inflammatory responses during demyelination, given the relevance to MS pathology, for completeness, we sought to introduce some of the state-of-the-art research relevant to PACAP/VIP roles in myelination. The gene discussed is ADCYAP1; the disease is myeloid sarcoma.