RAP1A and osteosarcoma: Circular RNAs (circRNAs) also contribute to Rap1 regulation by acting as sponges [97,98]: circRNA_103801 and circRNA_104980 modulate Rap1-related signaling pathways in osteosarcoma through sequestration of miRNAs such as miR-370-3p and miR-1298-3p [99,100].