IL6 and macrophage activation syndrome: The immune response in COVID-19-induced ARDS appears similar to those seen in macrophage activation syndrome (MAS) and secondary hemophagocytic lymphohistiocytosis (sHLH).20,31 McGonagle et al explored COVID-19 pulmonary immunopathology and described the potential benefits and disadvantages of IL-6 antagonism in patients with severe inflammatory responses.31 Clinical and laboratory manifestations of a MAS/sHLH picture seen in systemic onset juvenile inflammatory arthritis were compared to potential MAS complications with COVID-19-infected patients.