NPPB and congestive heart failure: For the interested reader, elucidation of utilizing a branch of mathematics known as combinatorics and step-by-step mathematical deduction applied to the BV – BNP feedback control system (as demonstrated in Additional file2: Appendix 2) has led to plausible explanations for our study findings, and lent support to the important hypothesis that ‘anatomical’ and ‘functional’ anephric patients inflicted with CHF should effectively have similar natriuretic response behavior.