Willner N, et al. - In this study researchers compared Semaphorin 4D (Sema4D) and N terminal pro brain natriuretic peptide (NT-proBNP) serum levels between patients diagnosed with heart failure (HF) and controls. They also assessed the correlation between Sema4D and NT-proBNP levels and analyzed Sema4D serum levels in HF patients during acute exacerbation and remission. They found that relative to healthy controls, HF patients had significantly higher Sema4D serum levels, which rapidly attenuated with clinical improvement, which may indicate the inflammatory nature of HF. Possibly, Sema4D can be used as a diagnostic biomarker of acute HF.