Digital image analysis of synovial tissue demonstrated clear IL-20 expression with comparable overall scores in both patient groups (median Integrated Optical Density (IOD) (range)): PsA, 60,064 (1,588 to 567,696); RA, 68,554 (1,171 to 530,218) (Figure 1B). This evidence concerns the gene IL20 and rheumatoid arthritis.