APP and breast angiosarcoma: Based on this, they attempt to prognosticate BA using biomarkers by analysing plasma samples for amyloid precursor protein (APP) as a biomarker in 30 BA infants and 10 age-matched controls.15 Biomarkers have been studied in BA for screening, diagnosis, prognostication of native liver survival, estimation of degree of fibrosis and clinically significant portal hypertension.