This study was approved by the ethical committee of Henan Provincial People's Hospital. The participants who agreed to be enrolled in this study were required to sign an informed consent. A total of 53 pairs of CRC tissue and adjacent normal tissue (ANT) specimens were collected between 2015 and 2016. Before the surgical procedures, none of the study participants had undergone radiotherapy, chemotherapy, or targeted therapy. After surgical resection, the specimens were immediately frozen in liquid nitrogen.