TNF and infection: Recent studies have confirmed that in vitro exposure of primary human cardiac pericytes to SARS-CoV-2 wild-type strains or alpha and delta variants resulted in infection, whereas exposure to recombinant S protein alone altered signaling and function, including: (1) increased migration, (2) impaired capacity in promoting the vascular network of endothelial cells (ECs), and (3) increased secretion of proinflammatory cytokines (IL-1 β, IL-6, TNF- α, and MCP-1) and pro-apoptotic factors (Fig. 2).