CSF2 and COVID-19: Recent studies on COVID-19 demonstrated that the lymphocyte counts in the peripheral blood were remarkably decreased and the levels of cytokines in the plasma from patients requiring intensive care unit (ICU) support, including IL-6, IL-10, TNF-ɑ, and granulocyte-macrophage colony-stimulating factor, were significantly higher than in those who did not require ICU conditions (2, 18).