Here, we discovered that the frequency of CD39+γδ Tregs, which positively correlated with poor prognosis, was significantly higher in right-sided colorectal cancer (RSCRC) than in the left-sided CRC (LSCRC). To explore the molecular mechanism leading to the difference of CD39+γδ Tregs derived from RSCRC and LSCRC, we collected fresh tissue samples of RSCRC with high expression of CD39+γδ Tregs and the LSCRC with low expression of CD39+γδ Tregs detected by flow cytometry and identified differential proteins by LC-MS based quantitative proteomic analysis with tandem mass tag (TMT)