The purpose of this Funding Opportunity Announcement (FOA) is to support basic and clinical mechanistic research on Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and Coronavirus Disease 2019 (COVID-19) susceptibility, routes of infection, course of disease, morbidity and mortality in people with pre-existing diseases, or adverse acute or chronic outcomes in organs, tissues, and biological systems of specific interest to NIDDK.