FGF18 and COVID-19: In addition to elevating acute phase proteins such as C-reactive protein [55] and fibroblast growth factor 18 (FGF18), an increased concentration of fibroblast growth factor, granulocyte colony-stimulating factor (G-CSF), granulocytes, and monocytes colony-stimulating factor (GM-CSF) has been linked to hospitalized COVID-19 patients compared with healthy controls [56].