GSN and COVID-19: Others, such as peptides from the kidney and inflammation marker CST331,38, changed drastically during critical COVID-19 cases, indicating the possibility of kidney dysfunction in severe infection6 and peptides associated with the calcium-regulated, actin-modulating protein gelsolin (GSN45) whose reduced abundances were associated with worse outcomes41 (Fig. 3c, d; Supplementary Data 5—Kendall ́s Tau trend test_WHO).