Hansen et al. investigated the predictive value of circulating miR-126 in mCRC patients receiving first-line chemotherapy combined with bevacizumab. Blood samples of patients were collected before treatment (baseline), 3 weeks after treatment and at progression. Evaluation of miR-126 expression in plasma showed that non-responders had an increase in miR-126 level relative to baseline, while responders with decreased miR-126 alteration. The results indicated that changes in circulating miR-126 during treatment represented a possible biomarker for the response to anti-angiogenic containing therapy . M. Joerger’s study assessed the predictive value of circulating miRNA in patients with non-squamous NSCLC, receiving treatment with first-line bevacizumab and erlotinib followed by platinum-based chemotherapy at progression. MiRNA profiling in pre-treatment blood showed that 12 miRNAs were significantly associated with tumor shrinkage following bevacizumab/erlotinib treatment, with miR-665 being the strongest predictive marker. Patients with high miR-665 expression had a higher chance for tumor shrinkage. Furthermore, miR-223 was found to be associated with both TTP following bevacizumab/erlotinib treatment and TTP following second-line chemotherapy . Collectively, these studies indicate that tissue and circulating miRNAs could serve as predictive biomarkers for response to anti-angiogenic therapy.