On the contrary, the Leiden 85-plus Study, a population-based prospective study in 85-year old subjects from Leiden (the Netherlands), showed that in this age group C-Reactive Protein (a proxy for IL-6) was a significant predictor of circulating hepcidin levels, which in turn were relatively higher in a small subgroup (n = 29) with unexplained anemia (den Elzen et al., 2013). This evidence concerns the gene HAMP and anemia (phenotype).