Absence of the CD44 gene prevents sarcoma metastasis.

To test the role of the CD44 gene in tumorigenesis, mice with the min mutation of the APC gene or with the tm1 mutation of the p53 gene were crossed with CD44 knockout mice. The absence of CD44 gene products did not affect tumor incidence or survival; however, mice with disruption of the CD44 gene showed virtually aborted metastasis formation of osteosarcomas. This is in agreement with the role attributed to CD44 variants in the spread of cancer. Therefore, CD44 gene products are not essential for tumor incidence and growth but are important in regulating metastasis formation.