They also found that some upstream regulators (IFNG, PRL, TLR7, PRL, TGM2, TLR9, IL1B, TNF, NFKB, IL1A, STAT3, CCL5) were enriched in bronchoalveolar lavage cells in severe COVID-19 cases compared to the mild cases. The gene discussed is TLR9; the disease is COVID-19.