Research using multi-omics analysis (whole genome sequencing, RNA sequencing, proteomics, cytokine profiling and high-throughput immunophenotyping) combined with artificial intelligence has shown that increased level of ADAM9 metalloproteinase is responsible for the severe course of COVID-19 in a young patient cohort.
https://www.science.org/doi/10.1126/scitranslmed.abj7521