In the AppNL-G-F/NL-G-F cortex, gene expression of Ctss as well as Nfe2l2, Tgfbr2 and Gfap was already elevated at 5 months of age compared with wild-type mice (Fig. 5), suggesting its contribution in Aβ production at the early stage of AD development. Here, CTSS is linked to Alzheimer disease.