ERBB2 and cancer: Epidermal growth factor receptor (HER2) is also a target of interest in prostate cancer and is currently under investigation in 3 phase I/II clinical trials. The first one is the PETRA trial [17], an ongoing phase I/II, open-label, multi-arm study, investigating poly (ADP-ribose) polymerase inhibitors (PARPi), alone or in combination with anti-HER2 ADCs (trastuzumab-DXd) or anti-TROP2 ADCs (dato-DXd), as well as other anti-cancer agents.