Liao et al. analyzed blood samples from 30 acute AD patients and 30 age- and sex-matched healthy controls and found higher rates of transcription and secretion of MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, and MMP-12 by monocytes/macrophages from acute AD patients than in those from healthy controls [84]. Here, MMP1 is linked to Alzheimer disease.