MAPT and Brain atrophy: Recent studies have reported the mobilization of immune cells, including T cells, in the brains of patients with tauopathies, highlighting the potential role of these cells in disease progression.3-6 It was reported that depletion of T cells using an anti-CD3 antibody suppressed tau phosphorylation and brain atrophy in a mouse model of tauopathy,7 suggesting the significant impact of T cells on pathogenesis.