In the same manner, Bellman-Weileret al. found no significant relationship between anemia and ICU admission, but concluded that alterations in iron homeostasis -as a higher ferritin/transferrin ratio- reflected further risk of advanced disease and predicted the need for ICU admission.6 However, these findings were limited to those without iron metabolism variability, which resulted in a selection bias and a smaller sample included in the multivariate analysis. The gene discussed is TF; the disease is anemia (phenotype).