LIMD1 is a LIM domain-containing adapter protein that functions primarily as a tumor suppressor through multiple mechanisms. At the cellular level, LIMD1 localizes to focal adhesions and the nucleus, where it regulates cell-cell adhesion, cytoskeletal organization, and transcriptional repression 1. LIMD1 is essential for miRNA-mediated gene silencing by binding to the mRNA 5' cap structure via eIF4E and facilitating communication between the miRISC complex and translationally inhibited mRNA, thereby promoting P-body formation 2. LIMD1 acts as a hypoxic regulator by complexing with PHD2 and VHL to facilitate HIF-α degradation, and hypoxic induction of LIMD1 creates a negative feedback loop suppressing HIF-1 target gene expression 3. Clinically, LIMD1 functions as a validated tumor suppressor in lung cancer: Limd1(-/-) mice show predisposition to chemical-induced lung adenocarcinoma, and genetic inactivation accelerates tumorigenesis in K-Ras(G12D) mice 1. Approximately 45% of non-small cell lung cancers exhibit LIMD1 loss through deletion, loss of heterozygosity, and epigenetic silencing 14. LIMD1 copy number variation correlates with poor prognosis in lung adenocarcinoma patients 3. Conversely, the LIMD1-AS1 lncRNA is upregulated in breast cancer, glioma, and prostate cancer, promoting EMT, proliferation, migration, and invasion through distinct mechanisms including TGF-β/SMAD signaling enhancement and miR-29c-3p suppression 567.