RAC1 and neoplasm: We found that KDM6A decreased the active form of Rac1 and the F-actin content by upregulating ARHGDIB, and treatment with MBQ-167 could partly reverse the increased filopodia formation and invasive ability conferred by KDM6A knockdown, suggesting that KDM6A is involved in the cytoskeletal remodelling of BCa cells by regulating the ARHGDIB-Rac1 axis; additionally, targeting the ARHGDIB-Rac1 axis might have a potent effect on tumours with mutated or low expression of KDM6A in BCa patients.