In order to identify parameters that may early indicate further respiratory failure or severe ARDS requiring treatment in an intensive care unit (ICU), Baranovskii et al analyzed the differences in prothrombin time and international normalized ratio (INR) as well as in Fibrinogen and D-dimer levels between unvaccinated COVID-19 patients who had been transferred to an ICU within two weeks after admission and matching cohort of COVID-19 patients with stable course of the disease. Here, F2 is linked to COVID-19.