CD40LG and Autoimmunity: Using these criteria, only four of the 263 reference sera expected to be negative were positive for antibodies to SARS-CoV-2: (i) an IGeneX pre-pandemic era human sera showed an overall positive reaction for IgG antibodies and another for IgM antibodies; (ii) a serum from the autoimmunity reference panel with elevated IgG gave a positive reaction for IgG antibodies and another with rheumatoid factor for IgM antibodies.