Some mediators that are modulated in bronchoalveolar lavage fluid (BALF) from patients with severe COVID-19 include the chemokines CCL2/3/4/7/8 and C-X-C motif chemokine ligand (CXCL) 1/2/6, as well as the peptide hormone epiregulin (EREG) and members of the ephrin A family (EFNA1 and EFNA5). The gene discussed is EREG; the disease is COVID-19.