PCNA and rheumatoid arthritis: In order to investigate the effects associated with PVT1 knockdown on the symptoms of RA-FLS, including inflammation, proliferation and apoptosis, the percentage of increase of paw swelling of rats in the control, RA + sh-PVT1-NC and RA + sh-PVT1 groups was calculated using a thickness measurement, with the expression levels of TNF-α, IL-1β, IL-10, IL-4, Ki67, PCNA, Bcl-2, Bax and caspase-3 determined by ELISA, RT-qPCR, western blot analysis, EDU staining and flow cytometry.