Although deleterious mutations in the two tumour suppressors genes TP53 and RB1 are frequently associated with carcinomas, these are rare events within carcinoids, which have a lower mutational burden compared to that of carcinomas, and a higher prevalence of mutations in genes involved in chromatin remodelling (Fernandez-Cuesta et al., 2014). This evidence concerns the gene RB1 and carcinoma.