MME (membrane metalloendopeptidase), also known as neutral endopeptidase 24.11, is a zinc-dependent metalloproteinase that degrades bioactive peptides of up to 30 amino acids in length 1. The enzyme exhibits thermolysin-like specificity and plays critical roles in peptide catabolism: it cleaves opioid peptides (Met- and Leu-enkephalins) at Gly-Phe bonds, degrades bradykinin and substance P, and metabolizes natriuretic peptides including ANF and BNP 23. MME also displays UV-inducible elastase activity toward skin elastic fibers 4. Clinically, MME variants are significantly associated with late-onset axonal neuropathies. Approximately 35% of genetically solved cases of unexplained axonal neuropathies in patients over age 35 involve MME mutations 5. These variants typically follow incompletely penetrant autosomal-dominant or autosomal-recessive inheritance patterns, conferring susceptibility to Charcot-Marie-Tooth disease type 2T in aging populations. Functional studies demonstrate that common polymorphisms, particularly Val73, substantially reduce enzyme activity (21% of wild-type) and protein abundance through proteasome-mediated degradation and autophagy 6. Additionally, MME expression is dysregulated in lupus nephritis, where it serves as a potential renal biomarker 7. The enzyme's role in peptide degradation and its altered expression in disease states establish MME as important for neurological and renal homeostasis.