IL21 and temporal arteritis: A genome-wide methylation array of GCA versus non-GCA temporal arteries revealed hypomethylation of signature T cell CpG related to TCR/CD28 signaling, pro-inflammatory cytokine production (e.g., IFNG, IL6, IL21, IL23R, IL17RA), and the calcineurin (CaN)/ nuclear factor of activated T cells (NFAT) pathway [156, 157].