The high-penetrance cancer predisposition genes APC, BMPR1A, BAP1, FH, MEN1, PTEN, VHL, WT1, and TP53 (on top of their strong association with gastrointestinal tumors, melanoma, leiomyomatosis, multiple endocrine neoplasia, hamartomas, kidney tumors, breast cancer (BC), central nervous system tumors, and sarcomas, respectively) were also identified in OC patients and/or families [5,62,63,64,65,66,67,68,69,70], suggesting a potential wider cancer manifestation in these syndromes. This evidence concerns the gene APC and cancer.