During the study period, on a total population of 462,642 subjects registered in Treviso LHU, 1,727 (0.4%) received at least one incident ESA dispensing during the years 2009–2014; of these, 1,003 (58.1%) ESA users had at least one baseline and one follow-up Hb measurement [CKD = 583 (58.1%); cancer = 420 (41.9%)] (Fig 2). The gene discussed is GSTM1; the disease is chronic kidney disease.