Tregs present in GCA-inflamed TAs exhibit plasticity, produce cytokines (IL-17) and contribute to sustaining vascular inflammation.64 FOXP3+ cells were found to coexpress IL-17A by double immunofluorescence staining of GCA-TAs.64 However, the specificity of FOXP3 expression to Tregs is unclear as other cell types can express FOXP3 when activated.65 66 For more details on vasculitogenic T-cells in GCA, we refer to the review article by Watanabe et al. 67. Here, IL17A is linked to inflammatory response.