Using a neurotropic, attenuated JHM strain of mouse hepatitis virus (MHV-JHM) infection model of acute encephalomyelitis, which resolves into a persistent infection associated with demyelination, a recent study showed that TREM2 deficiency does not affect viral control or establishment of persistence, but is essential in the clearance of damaged myelin induced by viral infection [126]. The gene discussed is TREM2; the disease is viral infectious disease.