Serologically, in human cases where anti-OPXV IgG ELISA was positive and anti-OPXV IgM ELISA was negative, when a blood sample was collected at least 56 days after the onset of rash illness, given that the patient was not previously vaccinated for smallpox, was considered confirmed Mpox-positive [121]. The gene discussed is CD40LG; the disease is smallpox.