Similarly, Humm et al. [50] analyzed the applicability of NT-proBNP to differentiate the origin of feline pleural effusion in a comprehensive study with three objectives: (i) To determine whether NT-proBNP may be detectable also in pleural lavage and urine of cats with effusion, (ii) to establish whether NT-proBNP levels in pleural lavage and urine correlate with the values of NT-proBNP in plasma, and (iii) to determine whether NT-proBNP in pleural lavage and urine can be used to distinguish the cardiac and non-cardiac causes of pleural effusion. The gene discussed is NPPB; the disease is Pleural effusion.