The top-weighted features IL-6 (R = 0.55), PCT (R = 0.55), CRP (R = 0.52), IL-2R (R = 0.45), and Th/Ts (R = 0.23) were consistent with previously reported risk factors intimately associated with poor outcome of COVID-19 [4–6, 22, 23]. Here, CRP is linked to COVID-19.