ATM and early-onset autosomal dominant Alzheimer disease: Furthermore, we compared the transcriptional characteristics of these clusters with several previously defined microglia populations under different pathological and physiological conditions, including injury-responsive microglia (IRM) detected in lysolecithin (LPC)-induced demyelination, disease-associated microglia (DAM) found in Alzheimer's disease, axon tract associated microglia (ATM) in the developing brain, and senescence-associated secretory phenotype (SASP) identified in senescent microglia [8, 31] (Fig. 1F).