LAD1 (ladinin 1) is an anchoring filament protein that serves as a structural component of the basement membrane zone 1. In cancer contexts, LAD1 functions as an oncogenic driver through multiple mechanisms. In esophageal squamous cell carcinoma (ESCC), LAD1 specifically binds to LINC01305 to co-regulate cortactin (CTTN) and neuronal Wiskott-Aldrich syndrome protein (N-WASP) phosphorylation, mediating cytoskeletal reorganization that promotes metastasis 1. LAD1 also activates the PI3K/AKT signaling pathway to promote epithelial-mesenchymal transition (EMT) 1. In gastric cancer, LAD1 competitively binds to vimentin, preventing its interaction with the E3 ubiquitin ligase MAEA, thereby reducing K48-linked ubiquitination and increasing vimentin protein levels to promote cellular invasion, migration, and chemoresistance 2. LAD1 is significantly upregulated in lung adenocarcinoma tissues, particularly in cancer cells, and its knockdown inhibits cell migration and invasion 3. Clinically, elevated LAD1 expression correlates with poor disease-free survival and overall survival in gastric cancer patients 2, late clinical stage and lymph node metastasis in ESCC 1, and serves as an independent prognostic factor in lung adenocarcinoma 3. LAD1 promoter methylation is also incorporated into prognostic marker panels for clear cell renal cell carcinoma 4.