YBX1 and cancer: This approach possesses several advantages: 1) Signal transduction inhibitors as molecular targeting therapies for cancer have been clinically validated with compounds such as trastuzumab (Herceptin®), imatinib mesylate (Gleevec®) and gefitinib (Iressa®), 2) CPPs have the potential to provide therapeutic options for triple-negative and trastuzumab-resistant breast cancer as well as prostate cancer, and, 3) Since the YB-1 pathway has been implicated in many different cancer types, the technology has broad utility.