We treated several MM cell lines with QA-68, dBRD9-A, and EA-89 and, similar to AML and ALL, we observed QA-68 or dBRD9A to more potently inhibit cell proliferation than EA-89 with a concomitant decrease in BRD9 protein (Fig. 6A, B and Supplementary Fig. 9). Here, BRD9 is linked to Miyoshi myopathy.