In a comprehensive multitissue gene expression profiling study (Gómez-Carballa et al., 2022), decreased expression of CAMP and S100A8/S100A9 genes in patients with severe COVID-19 was observed, while another study detected the upregulation of SCL25A37 among patients with severe COVID-19 (Policard et al., 2021). Here, S100A9 is linked to COVID-19.