Abstract: The present disclosure discloses the Twa1 gene and its expression products and applications. This disclosure first discovers and verifies the role of the Twa1 gene and its expression product in the occurrence and development of cancer. The Twa1 gene and its expression product has the ability to promote cell proliferation, growth, migration, invasion, and tumor formation, thereby providing a diagnosis of malignant tumors. This disclosure also provides new targets and strategies for inhibiting or interfering with the occurrence and development of many malignant tumors. The present disclosure provides an expression vector containing the Twa1 gene and a transgenic cell line and host bacteria containing the expression vector.