KMT2C and breast cancer: Loss-of-function mutations of MLL3 are also common in other hematologic malignancies, such as multiple myeloma [17], as well as in solid tumors, including medulloblastoma [18], bladder [19], liver [20], gastric [21], pancreatic [22], prostate [23], ovarian [24], esophageal [25], colorectal [26], and breast cancers [27], suggesting an important role for MLL3 as a tumor suppressor.