In a pilot study of 33 hospitalized patients during the first pandemic wave, we found that sequential analysis of ADMA and SDMA in blood samples taken on the first day of hospitalization for COVID-19 significantly improved the ability to predict in-hospital mortality as compared to traditional risk scores and biomarkers like SOFA, leukocyte count, C-reactive protein, and pro-calcitonin15. This evidence concerns the gene CRP and COVID-19.