A recent study using another mouse model of AD that overexpresses human wild-type tau detected increased TG2 mRNA and protein levels in the dorsal raphe nucleus compared to wild-type mice at a relatively young age when depressive-like behaviors were noted, suggesting a role of TG2 in tau pathology in the prodromal phase of AD prior to the onset of cognitive decline [137]. The gene discussed is TGM2; the disease is Alzheimer disease.