PTEN and breast cancer: To determine if NOTCH1 and NOTCH2 alterations could be regulating PTEN in tumor biopsies, we examined the same TCGA breast cancer cohort that we analyzed for EZH230,31,34, and found that the presence of NOTCH1 or NOTCH2 mutations in breast cancer (about 3% of cases) correlated with reduced PTEN expression30,31 (Fig. 5f).