S100A6 and Alzheimer disease: For example, eliminating C5aR1 reduced expression of Inpp5d (SHIP1), which reduces phagocytic capabilities in plaque-associated microglia [45], S100a6, which is found in plaque-associated astrocytes [79], and Stat3, which induces astrocyte reactivity in the 5xFAD model and astrocyte-mediated pro-inflammatory cytokine release in the APP/PS1 model [48, 80], all of which are upregulated and appear to play a detrimental role in human AD brain or mouse models of AD.