After applying LASSO analysis, 13 of the 29 candidate clinical parameters were further screened; 25(OH)D, length of symptoms, WBC count, D dimer, CRP, ferritin, albumin, mechanical ventilation, IL-8, ALT, pleural effusion, polylobular infection, and MP DNA copies (Supplementary Figure 1). Here, CXCL8 is linked to Pleural effusion.