The circRNAs hsa_circ_0024107 derived from the MMP1 gene and hsa_circ_0044518 derived from the COL1A1 gene are over-expressed in CRC patients, and they both act as sponges for many miRNAs; additionally, their up-regulation is closely related to the development and progression of CRC [22]. The gene discussed is MMP1; the disease is colorectal carcinoma.