Even though there is no extensive evidence linking radiotherapy with the development of clonal fibroepithelial polyps, radiation-induced (or even spontaneous) mutations of genes involved in hamartomatous disorders such as PTEN may evolve in and imitate benign proliferations of known germline syndromes such as Cowden; indeed, analogous disorders may be due to germline or acquired mutations of the same genes, e.g. inborn and acquired autoimmune lymphoproliferative syndromes (ALPS) [51–60]. This evidence concerns the gene PTEN and autoimmune lymphoproliferative syndrome.