Mizukane et al. reported an extremely rare case of a 76-year-old Japanese who developed hemophagocytic syndrome due to fulminant M. pneumoniae pneumonia, and they found that elevated sIL-2R, IL-6, and IL-10 levels may be caused by severe mycoplasmal pneumonia [9]. The gene discussed is IL6; the disease is Mycoplasma pneumoniae pneumonia.