PBMCs derived from COVID-19 patients and stimulated in vitro showed an increase in expression of CCL2, CXCL10, Eotaxin, and IL-1RA, and stimulation of CD8+ T cells were associated with an increase in IFN-γ levels, which indicates the functional responsiveness of these cells (Mathew et al., 2020). The gene discussed is CCL2; the disease is COVID-19.