CD274 and COVID-19: Ciaglia et al. (2021) found that long-lived individuals who are less susceptible to COVID-19 infection had higher levels of BPIFB4 protein circulating their blood than old healthy people and was even lower in COVID-19 infected patients. Sabbatino et al. (2021) suggests that the Programmed death-1 (PD-1) and its ligand programmed deathl-igand1 (PD-L1) has a potential prognostic role in COVID-19 and can be studied as target for future treatment.