FZD4 and rheumatoid arthritis: Beyond these specific examples, numerous ceRNA regulatory networks have been implicated in RA-associated apoptosis, including circ_0003972/miR-654-5p/FZD4 axis, circMAPK9/miR-140-3p/PPM1A axis, circASH2L/miR-129-5p/HIPK2 axis, and circ-AFF2/miR-650/CNP axis (97–100).