Accordingly, we crossed the APP/PS1 transgenic 5xFAD mouse model of AD (Tg thereafter) [19] with mice deficient in MT5-MMP (MT5−/−) [14] to generate a new bigenic TgMT5−/− strain and evaluate the impact of MT5-MMP deficiency in this AD mouse model. Here, PSEN1 is linked to Alzheimer disease.