MicroRNAs are pivotal regulators for RNA silencing and post-transcriptional regulation of gene expression under physiological as well as pathological conditions. MicroRNAs can be detected in tissues and in most biologic fluids including serum, plasma and urines. Secreted microRNAs are either incorporated into microvesicles or circulate bound to proteins. In both cases microRNAs are protected from RNase degradation so that they may remain intact for long periods of time. Therefore they might represent potential new biomarkers. We analysed expression of 800 miRNA’s using nCounter Nanostring technology in 3-D cell culture models (organoids), formalin fixed paraffin embedded tissues as well as plasma and urine from cancer patients. Potential clinical applications of microRNA detection for cancer patients’ management will be discussed.