LGALS9 and COVID-19: Interestingly, among sICLs, the soluble variants of both co-stimulatory molecules CD40L and Galectin-9 exhibited elevated levels in severe COVID-19 patients (Figures 2A, B), whereas the soluble form of the co-inhibitory molecule B7-H3 did not display any noticeable pattern (p = 0.3886, Figure 2C), and, if any, a reduction in its expression in patients with severe COVID-19.