GPR34 and neoplasm: The Hom-MG-1 subgroup highly expressed the innate characteristic genes of microglia (Tmem119, P2ry12, Crybb1, Cst1, Gpr34, and Cx3cr1), poorly expressed tumor activation-related genes, and expressed early activation genes to a certain extent (Jun, Junb, Jund, and Fos).