TPM4 (tropomyosin 4) is an actin-binding protein that plays crucial roles in cytoskeletal organization and has emerged as an important oncogene in multiple cancer types 1. The protein binds calcium and stabilizes actin filaments, contributing to cellular structural integrity 2. In cancer contexts, TPM4 demonstrates significant diagnostic and prognostic value across multiple tumor types, with overexpression consistently associated with poor patient outcomes 34. Mechanistically, TPM4 promotes cancer progression through several pathways: it enhances cell migration and invasion potentially via extracellular matrix remodeling 1, activates the Jak/STAT-SOX2 pathway contributing to confused cell identity in esophageal squamous cell carcinoma 5, and modulates ferroptosis through SCD1 regulation in gastric cancer 4. TPM4 expression correlates with immune cell infiltration and affects response to immunotherapy 13. Clinically, TPM4 serves as a valuable biomarker in extracellular vesicles for non-small cell lung cancer diagnosis 6 and can form targetable fusion proteins such as TPM4:NTRK1 in malignant phyllodes tumors, which respond to targeted therapy with larotrectinib 7. These findings establish TPM4 as both a prognostic marker and potential therapeutic target across multiple cancer types.