Consistent in-frame internal tandem duplications of BCOR characterize clear cell sarcoma of the kidney

Hajime Okita and colleagues show that clear-cell sarcoma of the kidney (CCSK) is characterized by recurrent in-frame, internal tandem duplications in BCOR . They detected BCOR alterations in all 20 CCSK tumors analyzed but not in any other pediatric renal tumors, suggesting a specific role for these in-frame duplications in driving CCSK oncogenesis.