In addition, we found Ctsz to co-localize with the lysosomal marker CD68 in structures of up to 4–5 μm in diameter, resembling the vacuole-like structures observed along the processes of Iba1+ microglial cells in the AD brain, lending additional support to Ctsz being involved in the CNS myeloid cell response to Aβ in AD. This evidence concerns the gene CTSZ and Alzheimer disease.