SELP and COVID-19: In parallel, plasma P-selectin and CD40L levels were analyzed as platelet-activation-dependent markers and compared to controls; soluble P-selectin was significantly higher (p = 0.0072) in non-survivors (Figure 1E), while CD40L values were significantly augmented in both COVID-19 subgroups (p = 0.0012 and p = 0.0022, respectively), but no difference was observed between survivors and non-survivors (Figure 1F).