Heterozygous germline pathogenic variants in PTEN are associated with a range of disorders that are known under the umbrella term ‘PTEN hamartoma tumour syndrome’ (PHTS) [74] and include Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome, PTEN-related Proteus syndrome, and PTEN-related Proteus-like syndrome. The gene discussed is PTEN; the disease is Bannayan-Riley-Ruvalcaba syndrome.