TPD52L1 (TPD52 like 1) is a cytoplasmic protein member of the D52 gene family that plays multifaceted roles in cellular signaling and differentiation. As a structural protein, TPD52L1 contains coiled-coil and PEST domains 1, enabling protein-protein interactions and homodimerization [GO annotations]. The protein localizes to the cytoplasm and perinuclear regions [GO annotations], with capacity to interact with various binding partners including PLP2 and RAB5C 2. Functionally, TPD52L1 promotes osteogenic differentiation of mesenchymal stem cells by activating the Wnt/β-catenin signaling pathway and upregulating osteoblast markers (osteocalcin and alkaline phosphatase) 3, suggesting therapeutic potential for osteoporosis repair. Unlike its paralog TPD52, TPD52L1 does not directly interact with ADRP to regulate lipid droplet formation 4. Clinically, TPD52L1 serves as an oncogenic fusion partner with ROS1 kinase in 1-2% of non-small cell lung cancers, generating constitutively active fusion proteins that drive proliferation via Ras/Raf/MEK/ERK and PI3K pathways 56. Additionally, TPD52L1 was identified as an independent prognostic biomarker for hepatocellular carcinoma survival in competitive endogenous RNA networks 7. These findings underscore TPD52L1's dual role as both a potential therapeutic target for bone regeneration and a cancer-associated protein.