TREM2 suppression in BV2 microglia promoted the inflammatory responses of M1 microglia, and the upregulation of TREM2 led to the promotion of M2 polarization and the alleviation of microglial inflammatory responses, indicating that TREM2 in microglia could lead to the transformation of M1 microglia into the M2 phenotype, leading to anti-inflammatory effects in PD [145]. The gene discussed is TREM2; the disease is Parkinson disease.