PTPN20 (protein tyrosine phosphatase non-receptor type 20) is a non-transmembrane tyrosine phosphatase that functions as a regulator of actin polymerization and NF-κB signaling. The enzyme exhibits catalytic activity toward tyrosyl-phosphorylated substrates and is dynamically localized to sites of actin polymerization in response to extracellular stimuli including epidermal growth factor, osmotic stress, and integrin ligation 1. PTPN20 possesses a dynamic subcellular distribution, targeting the nucleus, microtubule network, and actin-rich membrane structures 1. In triple-negative breast cancer, PTPN20 promotes metastasis by activating NF-κB signaling through dephosphorylation of p65 at serine 468, preventing its binding to COMMD1 and protecting p65 from proteasomal degradation 2. Elevated PTPN20 expression correlates with enhanced cell migration, invasion, and lung metastasis in vivo 2. PTPN20 has also been identified as a significant prognostic marker in Helicobacter pylori-related gastric cancer, where it associates with immune cell infiltration and tumor mutational burden 3. These findings suggest PTPN20 represents a novel therapeutic target across multiple cancer types, with potential utility as a prognostic biomarker.