Further, we examined The Cancer Genome Atlas (TCGA) for endometrial cancer and found genetic alterations in 95% (229/242) of patients in several key components of the PI3K-mTOR pathway, including PI3KCA (57%), PTEN (67%), PIK3R1 (33%) and mTOR (12%) (Figure 1F). Here, PIK3R1 is linked to endometrial cancer.