In previous studies, nonparametric RIs using the same Immulite® EPO assay in 170 healthy adults with a normal hematocrit ranged from 4.3 to 29.0 IU/L (median = 10.6 IU/L), and in 129 adults not screened for anemia, it was 3.3–23.4 IU/L [23,24]. The gene discussed is EPO; the disease is anemia (phenotype).