ACAAI Board Practice Exam 2026 – 400 Free Practice Questions to Pass the Exam

Activated, degranulating basophils express the cell surface marker CD63. This marker is a member of the integrin family and is commonly associated with the activation of various immune cells, including basophils. When basophils become activated, they undergo a process of degranulation, where they release inflammatory mediators like histamine and cytokines. The expression of CD63 is an important indicator of this activation process, as it appears on the surface of basophils after they have been stimulated by allergens or other immune triggers.

Understanding the role of CD63 can be crucial for recognizing basophil activation in various allergic and inflammatory conditions. This distinction is particularly important in contexts such as allergy testing and research on the mechanisms of allergic responses, where identifying activated basophils can provide insight into the underlying immune processes.