CHI3L1 and COVID-19: Acute COVID-19 was associated with a significant elevation in pro-inflammatory cytokines with eleven markers being associated with disease severity categories (namely IL-1β, IL-2, IL-6, IL-10, IL-18, IL-23, IL-33, TNF-α, IP-10, G-CSF and YKL-40).Many of the markers were highly correlated and reflect the known hyper-inflammatory phenotype of severe COVID-19 (36).