However, a reduction in tau hyperphosphorylation has been reported in an AD mouse model after blocking antibodies of the PD1/PDL1 axis (Baruch et al., 2016; Rosenzweig et al., 2019; Schwartz et al., 2019), suggesting that PD1 blockade may regulate tau hyperphosphorylation by affecting the activity of some key kinases. This evidence concerns the gene MAPT and Alzheimer disease.