Since complements and PAR1 in brains, known substrates of Gzmk, have important roles in AD (93, 94), and the close interaction between Gzmk+ CD8 T cells and microglia, it is particularly interesting to examine the function of Gzmk+ CD8 T cells in AD using specific inhibitors or knock-out mouse models. The gene discussed is CD8A; the disease is Alzheimer disease.