F11r, also known as Junctional Adhesion Molecule -A (JAM -A), is a transmembrane protein belonging to the immunoglobulin superfamily of cell adhesion molecules. It is present in epithelial cells, endothelial cells, leukocytes, and blood platelets. In epithelial and endothelial cells, it is involved in tight junction formation, maintaining cellular layer integrity. In leukocytes, it plays a role in transmigration through the vascular wall. It also participates in various biological processes like paracellular permeability, angiogenesis, and platelet activation [1,2].

Genetically engineered mice lacking F11r in blood platelets showed that the protein acts as a negative regulator of a key mechanism triggering platelet aggregation, as these platelets were abnormally reactive [1]. In pancreatic cancer cell lines, knocking down F11r led to decreased cell proliferation, loss of invasiveness, cell cycle arrest in G1 phase, and enhanced apoptosis, suggesting it could be a therapeutic target [3]. In prostate cancer, LINC01146 upregulates F11r to facilitate malignant phenotypes, regulated by TGF -β [4].

In conclusion, F11r is crucial for maintaining cellular integrity, regulating platelet function, and influencing cancer cell behaviors. The gene knockout studies in mice and cell-based knockdown experiments have revealed its roles in thrombosis-related processes and cancer progression, providing insights for potential therapeutic strategies in these disease areas.