We compiled a list of 10 tumour suppressor genes (that is, APC, ATM, CDKN2A, ERBB4, NF1, PRKDC, PTEN, SMAD4, SMARCA4 and STK11) that recur in human lung cancer based on publicly available tumour sequencing data and the Catalogue Of Somatic Mutations In Cancer (COSMIC) database2, 4, 5, 17. The gene discussed is SMAD4; the disease is neoplasm.