P2RX7 and Alzheimer disease: Although levels of the representative activation markers for microglia (AIF1, CD68, and LGALS3) were unchanged, expressions of BCO2, CAPN3, small G protein-associated genes (RASGRP3 and RAPGEF5), PACC1 (also known as TMEM206), and P2RX7 were significantly decreased in AD precuneus compared with controls (Fig. 4c).