Among sarcomas, these alterations characterize BCOR::CCNB3 fusion sarcoma, BCOR-internal tandem duplication (ITD)-positive primitive myxoid mesenchymal tumors of infancy (PMMTI), clear cell sarcoma of the kidney, subset of malignant ossifying fibromyxoid tumor (OFMT), and, less frequently, sarcomas with BCOR::MAML3 and ZC3H7B::BCOR fusions. The gene discussed is MAML3; the disease is sarcoma.