TNF and ischemic stroke: Mechanisms that increase risk of ischemic stroke in patients with Covid-19 are complex,5, 15 and include systemic inflammation and endotheliopathy.15, 40–42 Covid-19 can trigger a cytokine storm with upregulation of pro-inflammatory cytokines and chemokines such as tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1) and IL-6.15 Endothelial inflammation can induce a microvascular and macrovascular endotheliopathy that contributes to a pro-thrombotic state.15, 40