For example, EGF, transforming growth factor α, insulin-like growth factor 1, interleukin 6, keratinocyte growth factor, and other fibroblast growth factor family members are expressed in advanced prostate cancers and are believed to be important in fueling androgen-independent growth (Culig et al. 1994; Yeh et al. 1999). This evidence concerns the gene IGF1 and prostate cancer.