Bearing in mind that SMAD4 function is thought to be a characteristic of adenocarcinomas [33], triggering tumour progression in close association with further mutational drivers such as activating KRAS, involvement of comparable molecular pathways driving tumourigenesis of adenocarcinomas like BAC, UAC and CORAD could be suggested independently of the tissue origin. The gene discussed is SMAD4; the disease is minimally invasive lung adenocarcinoma.