Xie QK, et al. - Researchers investigated the prognostic significance of tumor-infiltrating lymphocytes (TILs) in metastatic colorectal cancer (mCRC) and the association of this prognostic benefit with the metastatic status and operation modality. Cox proportional hazards regression was used to assess the prognostic value of TILs, and patients newly diagnosed with stage IV CRC and surgically treated at the Sun Yat-Sen University Cancer Center between 2009 and 2014 were involved. They found better survival was strongly predicted by high TIL, independent of other patients’ clinicopathological characteristics, as corroborated in multivariable analysis. Overall, TILs level can serve as a prognostic biomarker in patients with mCRC but the operation modality and the metastatic status of patients should also be considered.