en Cancer Cancer Original Article Original Article Although colorectal cancer (CRC) is one of the most common cancers, the exact molecular mechanism of this cancer is not yet known. Circular RNAs (circRNAs), a class of non-coding RNAs, are newly identified and their role in the pathogenesis of various cancers has been shown. In this research, we studied the expression pattern and clinical importance of hsa_circ_000425 in CRC patients. After evaluation of hsa_circ_000425 expression rate in 4 CRC cell lines and 100 paired CRC tissues, the potential correlation between hsa_circ_000425 expression rate and clinicopathological parameters of CRC patients was analyzed. Additionally, receiver operating characteristic (ROC) curve was drawn to study the diagnostic value of hsa_circ_000425. A significant down regulation of hsa_circ_000425 was observed in both CRC tissues and cell lines. In addition, this downregulation was significantly associated with differentiation and lymphatic metastasis. The area under the ROC curve of hsa_circ_000425 was 0.839 (P < 0.001). hsa_circ_000425 may have a role in the pathogenesis of CRC and might act as a potential biomarker for the diagnosis and treatment of CRC; although further molecular studies must be performed in this regard. Circular RNA, hsa_circ_000425, colorectal neoplasm 266 272 http://ijmcmed.org/browse.php?a_code=A-10-1883-2&slc_lang=en&sid=1 Davood Mohammadi d.mohammadi@qums.ac.ir 100319475328460019122 100319475328460019122 No Department of Surgery, School of medicine, Qazvin University of Medical Sciences, Qazvin, Iran. Ali Bastani a.bastani@qums.ac.ir 100319475328460019123 100319475328460019123 No Department of Internal Medicine, School of Medicine, Qazvin University of Medical Sciences, Qazvin, Iran Yazdan Zafari z.zafari@qums.ac.ir 100319475328460019124 100319475328460019124 No Department of Hematology and Medical Oncology, School of Medicine, Qazvin University of Medical Sciences, Qazvin, Iran. Sohrab Esmeilazadeh s.esmaeilzadeh@qums.ac.ir 100319475328460019125 100319475328460019125 No School of Medicine, Qazvin University of Medical Sciences, Qazvin, Iran. Nafiseh Rastgoo n.rastgoo@qums.ac.ir 100319475328460019126 100319475328460019126 No School of Medicine, Qazvin University of Medical Sciences, Qazvin, Iran. Mohammad Bargahi m.bargahi@gmail.com 100319475328460019127 100319475328460019127 No School of Medicine, Qazvin University of Medical Sciences, Qazvin, Iran. Sahar Moghbelinejad smoghbelinejad@qums.ac.ir 100319475328460019128 100319475328460019128 Yes Research Institute for Prevention of Non-Communicable Diseases, Cellular and Molecular Research Centre, Qazvin University of Medical Sciences, Qazvin, Iran.