Grossberg et al. used a multiplex CLIA test for COVID-19 in an otherwise healthy cohort of adults and children in Colorado, and found that IgM antibodies against SARS-CoV-2 were generally detectable in the blood several days after initial infection, and the IgM levels and IgG levels were both elevated early (0–30 days following symptom onset). The gene discussed is CD40LG; the disease is COVID-19.