As the kidney is a key sensor for hypoxia [29], we considered the impact of anemia status and observed that the metabolomes of anemic piglets differed from those of marginal or optimal status, regardless of treatment (Figure S5A), with PC1 reflective of Hb concentration at sacrifice (Pearson correlation, R = 0.34, p = 0.039). The gene discussed is GSTM1; the disease is anemia (phenotype).