ST14 and carcinoma: Therefore, it seems that these characteristic bidirectional functions of ectodomain shedding of epithin/PRSS14 can cooperatively facilitate metastasis; its intracellular function can convert primary epithelial tumor cells into migratory mesenchymal carcinoma cells, while its extracellular function allows the degradation of the extracellular matrix and makes a path for the invading cells.