GPR174 and Alzheimer disease: Based on LASSO and RF, we identified 10 hub genes associated with M1 macrophages and AD, including ARMCX5, EDN3, GPR174, MRPL23, RAET1E, ROD1, TRAF1, WNT7B, OR4K2 and ZNF543. In an independent GSE44770 dataset, GPR174, TRAF1, ROD1, RAET1E, OR4K2, MRPL23, ARMCX5 and EDN3 were significantly different between the AD and healthy controls.