A strong positive correlation was observed between anti-M and anti-N (r = 0.8023, p < 0.0001) and between anti-S1 and anti-N IgM responses (r = 0.8073, p < 0.0001) (Fig. 2A, B, top panels) demonstrating similar IgM responses against these three SARS-CoV-2 proteins in COVID-19 patients. Here, CD40LG is linked to COVID-19.