A recent study with magnetic resonance imaging T2∗-relaximetry, involving 24 ET patients and 25 age-matched healthy controls, found increased iron content in both globus pallidus, in both substantia nigra, and in the right dentate nucleus of the cerebellum of ET patients (although only bilateral pallidum remained significant after correction for multiple comparisons).33 To our knowledge, neither iron content or HMOX1 and HMOX2 expression have been measured in neuropathological studies of ET patients yet. The gene discussed is HMOX2; the disease is essential thrombocythemia.