The literature also acknowledges that, due to the common overlap of iron deficiency and inflammation in older patients, the sensitivity of other markers used to identify iron deficiency anaemia such as ferritin and transferrin saturation may be reduced.24 These findings demonstrate that a significant proportion of participants with anaemia and a normal ferritin have evidence of co-existing inflammation (suggested by a raised CRP), potentially reducing the diagnostic value of this marker. The gene discussed is CRP; the disease is anemia (phenotype).