NOD2 and acute respiratory distress syndrome: The analysis that follows will focus on patterns of the microbial activation of human TLR, NOD-1, NOD-2 and NLRP3 among the NLR and RIG1 among the RLR, since these are the most commonly studied innate immune system receptors involved in sepsis, ALI, ARDS and COVID-19 research and, therefore, provide sufficient data for performing reasonable comparisons between these syndromes.