TGFB1 and pericardial effusion: Some pediatric patients with COVID-19 have developed Kawasaki disease (KD), a TGF-β mediated systemic immunoglobulin A (IgA) vasculitis causing cardiac complications, including acute myocardial infarction, myocarditis, left ventricular dysfunction, pericardial effusion and mitral valve insufficiency as well as a multi-system inflammatory syndrome (Jones et al., 2020; Harahsheh et al., 2020; Lee et al., 2015;, McCrindle et al., 2017; Shimizu et al., 2011).