SMARCA4, essential for mouse development [68] and embryonic stem cell pluripotency [26], has also been recognized as a tumor suppressor that is deficient in some cancers including small cell carcinoma of the ovary hypercalcemic type [10] and non-small cell lung cancer [69], but also found to be highly expressed and to have oncogenic roles in other cancers, including breast cancer and acute myeloid leukemia [42,70]. The gene discussed is SMARCA4; the disease is neoplasm.