The Insulin-Like Growth Factor Binding Protein 3 (IGFBP3) blood test is used to measure IGFBP3 levels, a protein that plays a key role in regulating the effects of insulin-like growth factor (IGF) on cells. This protein helps control cell growth and development and serves as an important indicator of endocrine health. The test is used to assess growth disorders, such as short stature, and to monitor certain conditions, including cancer. The results help doctors understand the patient’s health status and guide an appropriate treatment plan.