As SARS-CoV-2 belongs to the same large family of viruses, which includes those causing Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS), it should be assumed that the process of producing antibodies will be similar to that in case of other viruses belonging to that family, while the detection of IgG antibodies and IgM antibodies acting against SARS-CoV-2 may be an indication of infection. This evidence concerns the gene CD40LG and infection.