Interestingly, models in which three (APP, PS1, and tau) or five (two APP and three PS1) familiar AD mutations were concurrently inserted in mouse genomes were predominantly developed in a C57 background (Sterniczuk et al., 2010; Forner et al., 2021; Sil et al., 2022) or hybrid backgrounds with a B6 component. The gene discussed is MAPT; the disease is Alzheimer disease.