The cellular origins of c19orf10 in the synovium. Sections of rheumatoid arthritis synovial tissue stained with anti-c19orf10 stained red. (a) Sections stained with anti-CD68 to detect macrophage-like cells stained brown (arrow). (b) Sections stained with anti-CD55 to detect fibroblasts stained brown (arrows). There was a clear colocalization with CD55-staining cells, whereas the association with CD63-positive cells was much less apparent. c19orf10, chromosome 19 open reading frame 10.