LXN (latexin) is a metallocarboxypeptidase inhibitor that functions as a key regulator of cellular homeostasis and inflammatory responses across multiple organ systems. The protein acts as a hardly reversible, non-competitive inhibitor of carboxypeptidases CPA1, CPA2, and CPA4, and plays critical roles in inflammation regulation 1. LXN negatively regulates hematopoietic stem cell (HSC) population size by enhancing apoptosis and decreasing self-renewal through interaction with ribosomal protein subunit 3 (Rps3) 2. In vascular biology, LXN regulates endothelial cell cytoskeletal remodeling by controlling Filamin A proteolytic cleavage and nuclear translocation, with LXN deficiency improving vascular permeability and protecting against atherosclerosis 34. The protein also functions as an inflammatory suppressor in colitis through the HECTD1/Rps3/NF-κB pathway, where LXN deficiency leads to enhanced inflammatory responses 1. Additionally, LXN has been implicated in renal epithelial cell senescence and macrophage polarization in nephrolithiasis 5. LXN expression is altered in various pathological conditions including colorectal cancer, sarcopenia, and type 2 diabetes mellitus, suggesting its broad physiological significance 67.