F11, also known as the F11 Receptor (F11R) or Junctional Adhesion Molecule-A (JAM-A), is a transmembrane glycoprotein of the immunoglobulin superfamily. It is mainly located in epithelial and endothelial cell tight junctions and is also expressed on circulating platelets and leukocytes. F11 participates in regulating various biological processes such as paracellular permeability, tight-junction formation and maintenance, leukocyte transendothelial migration, epithelial-to-mesenchymal transition, angiogenesis, reovirus binding, and platelet activation [1].

No relevant findings from KO/CKO mouse models were directly mentioned in the provided abstracts. However, studies have shown that dysregulation of F11R/JAM-A may lead to pathological consequences and disorders in normal cell function. A growing body of evidence points to its role in carcinogenesis and invasiveness, though its tissue-specific pro-or anti-tumorigenic role remains debated [1]. Also, JAA-F11 antibody, which is specific for the Thomsen-Friedenreich antigen, extended the median survival time of mice with metastatic 4T1 breast tumors and inhibited lung metastasis [2].

In conclusion, F11 is involved in multiple crucial biological processes, and its dysregulation can have pathological implications. While its role in cancer progression is being explored, the tissue-dependent pro-or anti-tumorigenic nature is still under discussion. The study of F11 helps in understanding normal cell function and disease mechanisms, especially in the context of cancer [1,2].