MicroRNAs (miRNAs) play a central role in the pathogenesis of cancer. Deregulation of their function, either through altered expression levels or sequence mutation, has been linked to both initiation and progression of malignancy. In my PhD research. I applied a combination of high-throughput experimental strategies and advanced data-analyses to gain insights into the basic cellular functions, the molecular pathways and the genes regulated by miRNAs in order to have a better understanding of normal and deregulated miRNA function in cancer.