Patients were grouped by iron deficiency (ferritin < 30 μg/L and CRP ≤ 5 mg/L, n = 18), FID (ferritin < 30 μg/L and CRP > 5 mg/L, n = 17), anaemia of inflammation (ferritin ≥ 30 μg/L and CRP > 5 mg/L, n = 6), and anaemia of other causes (ferritin ≥ 30 μg/L and CRP ≤ 5 mg/L, n = 6). The gene discussed is CRP; the disease is nutritional disorder.