In contrast, in NF-κB/c-Rel (c-Rel−/−)-deficient mice, which spontaneously develop a late-onset PD-like phenotype, TREM2 levels increase with age both in c-Rel−/− and wild-type mice, thus demonstrating no specific role of TREM2 in neurodegeneration [30]. This evidence concerns the gene TREM2 and Parkinson disease.