Supervised machine learning algorithm (RF) was used to predict the COVID-19 severity and chronicity based on immune subset profiling and a 14-plex cytokine panel (TNF-a, IL-4, IL-13, IL-2, GM-CSF, sCD40L, CCL5, CCL3, IL-6, IL-10, IFN-g, VEGF, IL-8, and CCL4 (Patterson et al., 2021). The gene discussed is CCL4; the disease is COVID-19.