Liu et al. developed a web-based tool using k-means clustering to predict prognosis in terms of death or hospital discharge of COVID-19 patients using age, comorbidities (binary), and baseline log helper T cell count (TH), log suppressor T cell count (TS), and log TH/TS ratio (Liu et al., 2020e). Total T cell, helper T cell, and suppressor T cell counts were significantly lower and the TH/TS ratio was significantly higher in patients who died from infection as compared to patients who were discharged.