Chemotherapy-induced neutropenia refers to a common side effect of chemotherapy treatment in cancer patients, where the white blood cell count drops significantly, specifically affecting a type of white blood cell called neutrophils. Neutrophils are important in the body's immune response as they help fight infection, so when their levels are depleted, patients are at a higher risk of developing infections. This condition can be serious and potentially life-threatening, so it is important for healthcare providers to monitor patients closely and provide appropriate treatment, such as antibiotics or growth factors, to help prevent infections and support the immune system during chemotherapy treatment.