In a subsequent study, the method was further developed by omitting the IP step and expanding the assay to include a panel of 18 lysosomal proteins (AP2B1, APP, C9, CTSB, CTSD, CTSF, CTSL1, CTSZ, DDP7, GM2A, HEXB, LAMP1, LAMP2, LYZ, FUCA1, TNC2, TPP1, and ubiquitin) and applied to study AD and PD versus controls (136). The gene discussed is LAMP1; the disease is Alzheimer disease.