System Serological profiling (Fig. 1B) during the acute window of infection pointed to a significant deficit in IgG1 receptor binding domain (RBD), full S protein, S2, N-specific antibody, and S2-specific IgM levels in the nonsurvivor group between 3 and 9 days after symptom onset (Fig. 1C). The gene discussed is CD40LG; the disease is infection.