As S-adenosyl-L-methionine (SAM)-competitive EZH2 inhibitors are highly selective and are currently showing promise in clinical trials for lymphoma and malignant rhabdoid tumors36, we decided to test whether the preclinical EZH2 inhibitor UNC199937 could restore expression of PTEN in breast cancer cell lines. Here, EZH2 is linked to breast carcinoma.