PDLIM1 is a cytoskeletal adapter protein that functions as a platform for forming protein complexes involved in multiple physiological processes. Primary Function: PDLIM1 acts as a cytoskeletal organizer that brings kinases and other proteins to the cytoskeleton 1, and is required for assembly, disassembly, and organization of stress fibers in fibroblasts, including localization of ACTN1 and PALLD to stress fibers. It maintains cell polarity and facilitates fibroblast migration. Mechanism: PDLIM1 competitively binds alpha-actinin 4 (ACTN4), preventing excessive F-actin accumulation 2. In spermatogenesis, PDLIM1 orchestrates ectoplasmic specialization to regulate cytoskeleton assembly during spermatid release 3. PDLIM1 also regulates β-catenin expression in vascular endothelial cells 4. Disease Relevance: PDLIM1 is significantly downregulated in metastatic hepatocellular carcinoma, where loss promotes epithelial-to-mesenchymal transition and invasive capacity through Hippo signaling disruption 2. Conversely, PDLIM1 is upregulated during liver fibrosis progression and hepatic stellate cell activation 5. In diabetic retinopathy, PDLIM1 suppresses pathological retinal neovascularization 4. Clinical Significance: PDLIM1 serves as a potential prognostic marker for metastatic HCC and a therapeutic target for fibrosis and retinopathy.