Two other studies were conducted exclusively with males and reported a diminished expression of GFAP but, on the one hand, another form of vitamin D (D2 instead of D3) was delivered for a longer period (7 months) to a different transgenic mouse model of AD [59] and, on the other hand, vitamin D3 was administered for a very short period of time (3 weeks) to rats that were not engineered to mimic some of the symptoms of AD [17, 58]. The gene discussed is GFAP; the disease is Alzheimer disease.