Moreover, interferon (IFN)-γ and IL-17A present at the lesions of vasculitic arteries of TAK.[66] In addition, an increased number of tissue infiltrated CD8+ T cells were found in TAK than in GCA although their exact effect yet to be elucidated.[67,68] Despite the implication of T cells in mediating the disease process in TAK, an RCT for abatacept failed to show efficacy as GC sparing agent for TAK.[69] However, therapies targeting Th17 pathway have reported promising results. This evidence concerns the gene CD8A and temporal arteritis.