Interestingly, homozygous SMARCA4 mutations were mutually exclusive with alterations in other BAF members (ARID1A, ARID1B, ARID2, PBRM1, SMARCB1 and SMARCD1) in NSCLC and CUP (Fig. 1d). The gene discussed is SMARCA4; the disease is non-small cell lung carcinoma.