Although GDF5-6 and GDF6 were both able to simulate BMP signaling (Figure 2J, right), unlike GDF6, GDF5-6 was unable to rescue the growth inhibition by GDF6 silencing (Figure 2J, left), further supporting the critical role for the GDF6 prodomain in Ewing sarcoma. The gene discussed is GDF6; the disease is Ewing sarcoma.