CD274 expression levels were also increased in synovial tissue samples obtained from other stages of RA disease progression, namely UA (FC = 2.63, P = 1.02E-04), early RA (FC = 2.46, P = 1.07E-12) and established RA (FC = 2.39, P = 9.09E-14) (Fig 1B and Table 1). Here, CD274 is linked to rheumatoid arthritis.