1999, 2000; Gossmann et al. 2001). Other studies have shown good effects in treating polycythemia with angiotensin converting enzyme (ACE)‐inhibitors (Conlon et al. 1993; Gaston et al. 1993), perhaps by inhibiting sodium reabsorption leading to higher oxygen tension within the kidney and reduced EPO synthesis (Kristensen et al. 2009). The gene discussed is ACE; the disease is polycythemia.