Hypoxia and PHD inhibition do not induce Epo in P3Pro mutant kidneys. Shown are Epo mRNA levels in kidneys from P3Pro mutants and wild-type (Wt) littermate controls. (A) Exposure to acute anemic hypoxia induced by phlebotomy (measurements 24 hours after phlebotomy). (B) Exposure to chronic normobaric hypoxia (10% O₂ for 10 days). (C) Oral administration of PHD inhibitor GSK1002083A (PHI) for 2 days. Wt refers to Cre-negative littermates. Bars represent mean Epo mRNA levels ± SEMs (n = 3 or 4 per genotype and time point). *P < .05, **P < .01; ns, not statistically significant.