Laboratory examination: white blood cell (WBC) 4.6 × 109/L, hemoglobin (Hb) 139 g/L, platelet (PLT) 354 × 109/L, absolute neutrophil count (ANC) 2.86×109/L, C-reactive protein (CRP) 5.7 mg/L; Vitamin D determination 10.80 ng/ml; In addition, liver and kidney function, electrolyte, methyl work, disseminated intravascular coagulation, hemolysis, cell immunity, humoral immunity, iron deficiency full set are normal, as well as the results of the cardiac ultrasound, urinary tract ultrasound, chest computed tomography (CT) scan are also normal. Here, CRP is linked to Iron deficiency anemia.