Specifically, Yes-asssociated protein 1 (YAP1), Pellino E3 ubiquitin protein ligase 1 (PELI1), vascular endothelial growth factor A (VEGFA) and fibroblast growth factor 2 (FGF2) mRNAs were significantly upregulated in GCA patients with positive TAB compared to nonGCA controls, while the expression of Kruppel-like factor 4 (KLF4) mRNA was downregulated in GCA patients compared to nonGCA controls (Figure 3A). Here, KLF4 is linked to temporal arteritis.