HBEGF and head and neck carcinoma: While HB-EGF has been shown to be a potent chemotactic factor as well as a potent mitogen for fibroblasts, SMC and keratinocytes, the effects of HB-EGF for cancer cells have been reported as follows (5,42): i) HB-EGF gene expression has been detected in a variety of tumor-derived cell lines, including prostate, breast, colon, pancreas, ovarian, head and neck carcinoma and melanoma (17,21,22); and ii) enhanced HB-EGF gene expression in tumors such as pancreatic, liver and gastric tumors, has been detected compared to normal tissues (19–21).