CXCL13 and angioimmunoblastic T-cell lymphoma: Neoplastic TFH cells are postulated to have a role in AITL initiation and development through the deregulation of cytokines, such as interleukin-21 (IL-21), IL-4, and CXCL13 secreted by TFH cells that play important roles in germinal center cells’ interactions and activation [8].