One of the models used to study viral infection of microglia in vitro is through the use of human peripheral blood monocytes, which can differentiate into monocyte-derived microglia after culture with a serum-free medium containing M-CSF, GM-CSF, NGF, and CCL2 (Etemad et al., 2012; Rai et al., 2020). The gene discussed is CCL2; the disease is viral infectious disease.