Overexpression of miR-4478 promoted proliferation and invasion of RA FLS (Figures 7B–D, Supplementary Figures 4B,C), enhanced the expression of PCNA and Cyclin D1 (Figure 7E and Supplementary Figure 4D), and increased the levels of MMP-3, IL-1, and IL-6 (Figure 7F and Supplementary Figure 4E). Here, CCND1 is linked to rheumatoid arthritis.