PTPRC and uveitis: The flow cytometric analysis of the CD45+ monocytic cell population in HLA-B27-positive/-negative controls and patient samples with active or inactive AAU (HLA-B27-positive) or IAU (HLA-B27-negative) showed a stable frequency of peripheral blood monocytes, while the frequency in AAU patients increased during clinical uveitis inactivity (Figures 1A,C).