NLRP3 and COVID-19: Consistent with NLRP3-inflammasome activation, caspase-1 activation was detected on post-mortem lung tissues and mainly registered with lung-residing macrophages, localizing predominantly at the areas of alveolar injury and foremost-injured vasculature and thrombosis, hence supporting NLRP3-inflammasome activation as a putative mechanism contributing to immunothrombosis in COVID-19.