An orderly increase of α-L-fucosidase (AFU), myoglobin, uric acid, and MCHC and an orderly decrease of thrombin time, monocyte count, eosinophil count, RBC MCV, and RDW-SD were observed in CAP, COVID19-COM, and COVID19-SV patients, indicating that these CLIs may be used to distinguish CAP from COVID-19 and may suggest the probability of severe COVID-19 progression (see Multimedia Appendix 2). The gene discussed is MB; the disease is COVID-19.