NPPB and AL amyloidosis: Another study by Kumar et al. developed a revised staging system for AL-amyloidosis that improves patient risk stratification by combining cardiac biomarkers (NT-proBNP ≥ 1800 pg/mL and troponin-T ≥ 0.025 ng/mL) with serum-free light chain (FLC-diff ≥ 18 mg/dL) [53].