Severe anemia and hypoxia stimulate erythropoietin (Epo) production by the kidney (Haase, 2013; Kobayashi et al., 2016; Koury & Haase, 2015; Koury, Bondurant, & Koury, 1988; Lacombe et al., 1988; Obara et al., 2008; Semenza, Koury, Nejfelt, Gearhart, & Antonarakis, 1991). Here, EPO is linked to anemia (phenotype).