In particular, the SWI/SNF subunit SMARCB1 has been approved as an effective marker of metastatic or locally advanced epithelioid sarcoma sensitivity to tazemetostat [26,27,28], while SMARCA2, SMARCA4, ARID1A, and PBRM1 are potential marker candidates [91,92,93,94,105]. The gene discussed is ARID1A; the disease is epithelioid sarcoma.