Serial measurements of proBNP levels were available in 44% of our patients (data not shown), but the presence of pre-treatment proBNP levels above the age-adjusted cut-off values, and their variations due to cardiological therapy, anaemia, infections and renal disease, affected the specificity and predictive value of this biomarker, as previously reported (Dodos et al, 2008). The gene discussed is NPPB; the disease is kidney disorder.