In a study involving 285 COVID-19 patients, the median day of seroconversion for both IgG and IgM was 13 days post-symptom onset with 100% IgG seroconversion and 94.1% IgM seroconversion observed within 19 and 22 days post-symptom onset, respectively [56]. The gene discussed is CD40LG; the disease is COVID-19.