BMP6 and sarcoma: These observations are clinically important since we found that both overall and disease-free survival of sarcoma patients exhibiting high levels of RNF4 or BMP6 (but not RGMb) was shorter than that of patients exhibiting low RNF4 or BMP6 levels (Fig. 5E–G) Moreover, high RNF4 levels were associated with reduced overall survival, progress free survival, and disease-free survival (Supp.