ACE2 and acute respiratory distress syndrome: In order to investigate whether RBD can sensitize lung endothelium for pneumococcal pneumonia-induced ARDS and coagulopathy, we have generated transgenic mice, in which mouse ACE2 has been globally replaced with human ACE2 (global hACE-2 knock in mice), using CRISPR-Cas9 (Figures 7A, B).