PROS1 and COVID-19: The S protein is directly related to the human immune response to COVID-19 and, as such, has been one of the most studied and targeted proteins in SARS-CoV-2 research (Shang et al., 2020; Harvey et al., 2021; Jackson et al., 2022; Carabelli et al., 2023; Markov et al., 2023).