Tumor cell loss of expression of SMARCB1 protein (also called INI1), as shown in the example in Figure 6f, or (rarely) loss of SMARCA4 protein (also called BRG1) predicts mutations of SMARCB1 or SMARCA4, respectively, with SMARCA4-mutant AT/RT usually presenting at younger age. Here, SMARCB1 is linked to neoplasm.