PCNA and rheumatoid arthritis: In order to investigate the mechanism of PVT1 in RA-FLS inflammation, proliferation and apoptosis, the expression levels of TNF-α, IL-1β, IL-10, IL-4, Ki67, PCNA, Bcl-2, Bax and caspase-3 in the blank, sh-PVT1-NC, sh-PVT1, oe-PVT1-NC and oe-PVT1 groups were detected through the application of ELISA, RT-qPCR, western blot analysis, EDU staining and flow cytometry.