PRTN3 and rheumatoid arthritis: Transcriptomics analysis by RNA-Seq in synovial tissue biopsies from healthy donors (n = 28) and patients with OA (n = 15), ACPA+ rheumatoid factor (RF)+ arthralgia (n = 10), UA (n = 6), early RA (n = 57), and established RA (n = 95) revealed significantly higher CD38 expression as early as the arthralgia stage (compared to healthy controls, fold change (FC) = 4.5, P = 2.50E-04, Fig. 1a, Table 1) prior to established RA development.