Mechanistically, we found that this novel intronic circFGFR1int2 promoted FGFR1 expression by recruiting the transcription activators P65 (RELA) and FUS (fused in sarcoma), and by suppressing miR-4687-5p, which was found to be an inhibitor of FGFR1. The gene discussed is FGFR1; the disease is sarcoma.