A study on adult patients with panic disorder and agoraphobia found decreased levels of circulating CD19+ B lymphocytes compared to healthy controls (Schleifer et al., 2002), while other studies found increased numbers of leukocytes in child and adult patients with anxiety-related disorders (Uzun and Akıncı, 2021; Özyurt and Binici, 2019). Here, CD19 is linked to agoraphobia.