To understand the immune response against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infections, measurements, and monitoring of antibodies (mainly immunoglobulin g [IgG] and IgM) against SARS‐CoV‐2 have already been performed, and some studies reported that antibodies are useful diagnostic tools for SARS‐CoV‐2 infections.1, 2. The gene discussed is CD40LG; the disease is COVID-19.