TMPRSS4 (Transmembrane Protease, Serine 4): TMPRSS4 is part of the transmembrane serine protease family, found on the cell surface and responsible for activating proteins by cleaving peptide bonds. TMPRSS4 plays significant roles in both physiological and pathological processes, including cell migration, invasion, and the regulation of epithelial-mesenchymal transition (EMT), which is essential for development, wound healing, and cancer metastasis. Its overexpression has been associated with the progression of various cancers, making TMPRSS4 a potential biomarker for cancer diagnosis and prognosis.