Although, at present, the molecular mechanism of how the deletion of microglial Tgm2 leads to reduced anxiety and increased cognitive deficits still remains elusive, we have identified the phagocytic genes, such as Cq1a, C1qb and Tim4, to be down‐regulated in Tgm2 cKO microglia compared with WT controls. The gene discussed is C1QB; the disease is Cognitive impairment.