Lap3, also known as leucine aminopeptidase 3, belongs to the M1 family and catalyzes the hydrolysis of leucine residues from the amino termini of protein or peptide substrates. It is involved in protein metabolism and plays a role in multiple biological processes [3,8].

Lap3 has been implicated in various disease-related and physiological processes. In bovine mammary epithelial cells, IFN-γ stimulates Lap3, which is regulated by p38 and ERK MAPKs, to downregulate arginine levels via interfering with ASS1, contributing to malignant transformation. In breast cancer patients, Lap3 is upregulated [1]. In non-alcoholic fatty liver disease (NAFLD), cholesterol-induced upregulation of Lap3 in hepatocytes inhibits autophagy, and Lap3 could be a biomarker for NAFLD diagnosis [2]. In glioma, high Lap3 expression is correlated with malignancy grade and poor prognosis, and it promotes glioma cell viability, cell cycle progression, migration, and invasion [3]. In C2C12 myoblasts, suppression of Lap3 accelerates myogenic differentiation via the AKT-TFE3 pathway [4]. In sheep embryonic myoblasts, Lap3 impacts cell proliferation and myogenic differentiation [5]. In dairy cattle, Lap3 gene polymorphisms are associated with milk production traits and clinical mastitis [6]. In sheep and razor clams, Lap3 gene mutations are associated with growth traits [7,8].

In conclusion, Lap3 is a key enzyme in protein metabolism with diverse functions. Studies using different models have revealed its significance in diseases like breast cancer, NAFLD, glioma, and its role in physiological processes such as myogenic differentiation, cell proliferation, and growth. These findings suggest that Lap3 could be a potential therapeutic target and biomarker in relevant diseases and a candidate gene for improving production traits in animals.