LC-MS/MS and pathway analyses defined the IL-6 signaling as the most up-regulated pathway revealing the increase in CRP, LRG1, S100A12, SAA1, SERPINA3, SFTPB, TIMP1, and the decrease in ASH1L, CETP, CRISP3, F13B, GSN, IGFALS, IGFPB3, PARP9, PSRC1, and STOM in COVID-19 patients vs. controls. This evidence concerns the gene SERPINA3 and COVID-19.