RPL19 and rheumatoid arthritis: The PPI network constructed by DEGs between OA and RA was shown in Fig. 5C. In the top 20 connections of these three PPI networks, overlapped genes were shown in Fig. 5D. The top 10 hub genes identified between OA and RA (RPS6, RPS14, RPS25, RPL11, RPL27, RPS29, SNRPE, EEF2, RPL10A and RPL19) were selected for further experimental verification.