Bencsikova B, et al. - In this prospective study involving 36 patients, researchers ascertained if baseline levels of circulating T cell subsets serve as a potential biomarker of clinical outcome of metastatic colorectal cancer (mCRC) patients treated with an anti-VEGF-based regimen. Participants in the study were patients with histologically confirmed KRAS-tested metastatic adenocarcinoma of colon or rectum who started first-line treatment for metastatic disease. According to findings, the baseline level of circulating immune cells predicts the clinical result of first-line therapy with the bevacizumab anti-VEGF angio/immunomodulatory agent. Circulating immune biomarkers, namely the CD8:Treg ratio, detected patients with favorable results after therapy with 1st-line anti-VEGF therapy in the right-sided mCRC subgroup.