Jun et al. have recently reported that PLXNA4 induces tau phosphorylation by activation of Cyclin-dependent kinase 5 and glycogen synthase kinase-3β, which are known to be activated by SEMA3A in Alzheimer’s disease [37,38], suggesting the potential implication of the same pathway in the p-tau accumulation in CTE brain, and its reflection in CTE EVs. The gene discussed is MAPT; the disease is early-onset autosomal dominant Alzheimer disease.