NPPB and heart failure: The reliability of NT-proBNP as a biomarker results from a direct intracellular pathway connecting the amyloid-forming precursor protein, immunoglobulin LC, to the induction of kinases known to promote BNP expression, and it makes the use of NT-proBNP, a robust surrogate for survival unique from other applications (for example, heart failure) in which inconsistencies have justifiably warranted apprehension.