Kukla et al.: lower serum chemerin levels in COVID-19 patients compared to controls [45].Lavis et al., Amend et al.: higher plasma chemerin levels in severe COVID-19 patients compared to controls [48,54].Sulicka-Grodzicka et al.: no difference in serum chemerin levels between severe and non-severe patients [46].Esendagli et al.: higher serum chemerin levels in COVID-19 patients with good prognosis compared to patients with bad prognosis [47].Lavis et al.: higher plasma chemerin levels in deceased COVID-19 patients compared to recovered, and independent risk factor for mortality [54]. Here, RARRES2 is linked to COVID-19.