PKN1 and Familial prostate cancer: In our study, we provide evidence that TPα and TPβ can form complexes/associate with all three of the PRK isozymes, but that the association occurs in a cell-specific manner whereby PRK1 and PRK2 can both associate with TPα/TPβ endogenously expressed in the prostate cancer PC-3 cell line, while PRK3 only associates with TPα/TPβ when over-expressed in HEK293 cells.