The proportion of ferritin tests without accompanying CRP or hemoglobin tests was surprisingly high because most guidelines explicitly recommend screening for systemic inflammation and anemia in the workup of iron deficiency.4 Hemoglobin and CRP testing was associated with fatigue and with fewer previous primary care visits, suggesting that they were more commonly used in patients in whom a symptom-led search for iron deficiency took place rather than in episodes of care involving routine screening. The gene discussed is CRP; the disease is nutritional disorder.