Wip1-deficient mice are resistant to common cancer genes.

PPM1D encodes WIP1, a serine-threonine phosphatase that had previously been shown to be the driver oncogene of a 17q23 amplicon that is present in approximately 15% of human breast tumors. However, it is unknown whether it has any role in the remaining 85% of breast tumors. A recent study using Wip1-deficient mice revealed that blocking its function significantly impaired RAS and ERBB2-induced breast tumor formation, suggesting that the inhibition of Wip1 could be a broad-spectrum treatment for breast cancer. However, because of the structure of Wip1, the development of small molecule inhibitors is a significant challenge.