Since urine sampling is less invasive and easier than serum sampling, urinary NT-proBNP concentrations would have potential as a biomarker for self-monitoring of the status of cardiovascular risk and/or heart failure [22], if tools could be developed for the measurement of urinary NT-proBNP, similar to the self-monitoring devices for the urinary sodium-to-potassium ratio [23]. The gene discussed is NPPB; the disease is heart failure.