IL23A and temporal arteritis: The aims of this study were to investigate IL-12/23p40, IL-12p35, and IL-23p19 subunit expression in GCA lesions and their combination to conform different cytokines, to investigate the effect of glucocorticoid treatment on subunit expression, to analyze the relationship between subunit expression and glucocorticoid requirements, and to explore IL-12/23p40 function in GCA by exposing temporal artery sections to a neutralizing anti-human IL-12/IL-23p40 antibody.