IGFBP5 and Familial prostate cancer: However, stress-induced increase in several antiapoptotic genes, such as bcl-2, clusterin, insulin-like growth factor binding protein-2 (IGFBP-2), IGFBP-5 and heat-shock protein 27, have been shown to have important functions in the AI progression of prostate cancer after castration (Gleave et al, 1999; Miyake et al, 2000b, 2000c; Kiyama et al, 2003; Rocchi et al, 2004).