DPP4 and COVID-19: Recognizing that people with chronic kidney disease, who are often consuming a high-salt diet and commonly prescribed RAAS blocking drugs and/or DPP4-inhibitor and/or SGLT2 blocker, are at increased risk of severe COVID-19 outcomes, we studied the expression profiles of ACE2 and TMPRSS2 and other genes involved in the RAAS in the kidney and the heart in a rat model that mimics this phenotype (impaired kidney function combined with a high salt intake – most patients consume unfortunately several times more salt than they actually should control blood pressure).