Derived Joint to Blood Pool Ratios of individuals finally diagnosed with PMR (1.35 ± 0.23, (95%CI, 1.18–1.51)) were again significantly increased relative to blood pool-based ratios in GCA alone (0.88 ± 0.07, (95%CI, 0.83–0.93)) or GCA + PMR (0.96 ± 0.14, (95%CI, 0.85–1.06), p < 0.001, respectively; Supplementary Materials Figure S1b). The gene discussed is GCA; the disease is temporal arteritis.