identified a population of macrophages expressing high mRNA levels of key molecules of M1 macrophages (TNF, IL1B, and IL18), a cluster expressing M2 macrophages related genes (CD163, CCL13, CCL17, and CCL18), and two closely related clusters of macrophages characterized by high expression of IFITM3 and varying expression of IL1B in skin biopsies from AD patients by scRNA-seq (6). The gene discussed is CCL17; the disease is Alzheimer disease.