NRP1 and fibrosis: Considering the absence of heart failure prior to death in the autopsied population and our observation that fibrosis and increased TGF-β1 RNA levels accurately predicted disease severity in COVID-19 patients presenting to the ED, we hypothesize that increased systemic TGF-β1 expression might predispose patients to viral infection of the lung due to increased pulmonary expression of NRP-1 as a SARS-CoV-2 entry receptor.