Notably, the study uncovered an environmental trait-related signature influencing IL-6 expression via the transcription factor CEBP, distinguishing severe from mild cases and also highlighting the role of neutrophils and CD8+ T-cells as key contributors to interferon-related hypomethylation, providing a molecular basis for the cytokine storm observed in critical COVID-19 [90]. This evidence concerns the gene CD8A and COVID-19.