IGFBP3 (Insulin-Like Growth Factor Binding Protein 3) is a protein that binds to insulin-like growth factors (IGFs), regulating their availability and activity within the body. This regulation affects cell growth, development, and metabolism. IGFBP3 is extensively studied in cancer research, as it can either inhibit or enhance IGF effects depending on the cellular environment, making it a crucial factor in tumour growth and potential therapeutic strategies.