Of the 187 cases who had peripheral blood C‐reactive protein (CRP) tested, 178 (95.2%) had CRP < 8 mg/L, 8 (4.3%) had CRP > 8 mg/L (range: 8.8–35.8 mg/L), and 1 (0.5%) had CRP 56 mg/L who had co‐infection with M. pneumoniae and developed typical lobar pneumonia in the right lung. The gene discussed is CRP; the disease is coinfection.