TYK2 and Familial prostate cancer: In fact, overexpression of TYK2 (a member of the Janus family of non-receptor tyrosine kinases, JAKs) has been described in several malignancies, such as PCa and squamous cervical carcinomas, as well as in breast cancer cell lines [25], with some studies showing its involvement in enhancing prostate cancer invasion [26, 27].