APOE and amyloidosis: Pohlkamp et al. (16) extended this by showing that NHE6 depletion corrected ApoE4-mediated synaptic impairments and reduced amyloid plaque load even in the absence of ApoE4, indicating that accelerating early endosomal acidification broadly improves proteostasis and Aβ clearance, thereby reducing the formation of synaptotoxic amyloid species.