Over 90% of epithelioid sarcoma cases are characterized by loss of INI1 (also known as SMARCB1), conferring an oncogenic dependency on the enhancer of zeste homolog 2 (EZH2), the catalytic subunit of the chromatin remodeling polycomb repressive complex 2 (PRC2). The gene discussed is EZH2; the disease is epithelioid sarcoma.