ACTA1 and temporal arteritis: Phenotypic differentiation as well as migration of adventitial (myo)fibroblasts towards the intima and their contribution to neointima formation have been demonstrated using in-vivo animal models.110–112 Using murine vascular injury models, two groups demonstrated that labelled fibroblasts migrated from the adventitia to the intima, acquiring α-SMA expression during their migration.111 112 Findings of fibroblast functions observed in mechanical/endoluminal vascular injury and adventitial inflammation require validation in GCA.