In a preliminary report by Lee et al. (76), they tested the reactivity of antibodies to the receptor binding domain of COVID-19 Spike proteins using ELISA kits for IgA, IgM, IgG, and secretory Ab, comparing 15 milk samples from previously infected patients with SARS-CoV-2 and 10 negative control samples that were obtained before December 2019. The gene discussed is CD40LG; the disease is COVID-19.