While expression studies have indicated that mTOR signalling is upregulated in most PanNET tumours (Perren et al. 2000, Missiaglia et al. 2010), whole-exome and whole-genome sequencing studies have found mutations in negative regulators of the signalling pathway in only 12–15% of patient tumours (Jiao et al. 2011, Scarpa et al. 2017). The gene discussed is MTOR; the disease is neoplasm.