Furthermore, the known cancer/testis antigen Plac1 was reported to interact with Furin, a proprotein processing enzyme92, to degrade Notch1 into Notch1 intracellular domain (NICD) fragments that undergo nuclear translocation to suppress PTEN transcription93, forming a Plac1/Furin/Notch1/NICD/PTEN signalling mechanism that results in transcriptional repression of PTEN and allows for the hyperactivation of AKT signalling in breast cancer (BC) cells93. This evidence concerns the gene AKT1 and breast cancer.