CXCL12 and COVID-19: Our initial Luminex-based screening on plasma from critically ill COVID-19 patients from the first wave detected significantly higher levels of cytokines involved in recruitment and trafficking of neutrophils such as IL-8, G-CSF and SDF-1α, in accordance with previous reports showing that acute-phase COVID-19 patients have elevated neutrophil counts [6,20,22,42,43].