Using a SIPA1L3 mutant, we found that SIPA1L3 interacts with AMOT through its PDZ domain, which inhibits the binding of AMOT to Pals1-associtated tight junction protein and further decreases AMOT anchoring to tight junctions.<h4>Conclusion</h4>Our findings suggested that SIPA1L3 promotes tumorigenesis in lung cancer cells through its PDZ domain-mediated interaction with AMOT, suggesting that SIPA1L3 is a novel candidate gene that contributes to the malignant phenotype of lung cancer. This evidence concerns the gene SIPA1L3 and lung cancer.