AD significantly dampened AR signalling; expression of AR target gene, kallikrein-3 (KLK3, encoding PSA)20 was significantly downregulated (p = 0.03; Fig. 2A), and PSA expression was undetectable after 15 days AD (Fig. 2B), whilst AR mRNA and protein expression remained evident throughout (Fig. 2A,B). Here, KLK3 is linked to Alzheimer disease.