Updated project metadata. Colorectal cancer (CRC) is the third most common cancer worldwide and is a heterogeneous disease, with differences between cancer in the right colon, left colon, and rectum. In this study, plasma samples from CRC patients with varying stage (II or III), primary tumor location (right colon, left colon, or rectum) and survival (survived or died due to CRC) were studied with quantitative label-free proteomics using ultra-definition MSE. Patients were also divided into subgroups based on preoperative radiotherapy status and gender. Further analysis subsequently identified multiple plasma proteins whose expression differed depending on tumor stage, location, patient survival, preoperative radiotherapy status, or gender.