CD4 and temporal arteritis: In an effort to understand the possible added contribution of IC pathways to the dysregulation of CD4+ T cells in GCA, we aimed to 1: investigate the expression of different IC molecules on CD4+ T cells of GCA patients and compare it with age- and sex-matched healthy controls (HCs), 2: assess checkpoint expression at the vascular site in GCA and non-GCA biopsies and 3: determine the effect of VISTA-Ig engagement on CD4+ subset lineage differentiation.