IGFBP3 (Insulin-Like Growth Factor Binding Protein 3) is a protein that binds to insulin-like growth factors (IGFs), controlling their availability and activity in the body. This regulation influences cell growth, development, and metabolism. IGFBP3 is closely studied in cancer research, as it can either suppress or promote IGF effects depending on the cellular environment, making it a significant factor in tumor growth and potential therapeutic approaches.