A complete loss of SMARCB1 (testing INI1]) and SMARCA4 (testing BRG1) reactivity in the tumor nuclei is essential for the diagnosis of SMARCB1-deficient (Fig. 7C) and SMARCA4-deficient sinonasal carcinoma (Fig. 7F), respectively [59]. The gene discussed is SMARCB1; the disease is neoplasm.