MicroRNAs (miRNAs) direct post-transcriptional gene repression by binding to target mRNA 3′UTRs. Because approximately 50% of human miRNAs are organised into clusters (multiple miRNAs encoded within a single primary transcript), their coordinated expression provides an opportunity to function cooperatively. Neuroblastoma (NB), the most common extracranial solid tumour in children, is believed to originate from impaired differentiation of neural crest-derived cells during development of the sympathetic nervous system. To better understand the underlying molecular mechanisms and the regulatory role of miRNAs in NB, we have employed human induced pluripotent stem cells (iPSCs) as a model system to recapitulate sympathetic neuronal differentiation. Sequencing of the developmental time course identified developmentally regulated miRNA clusters, which were cloned into doxycycline (Dox)-inducible vectors to maintain their expression during iPSC neuronal differentiation. We find that sustained expression of the miR-17~92 cluster results in the downregulation of multiple transcription factors, neuronal differentiation genes, and a large cohort of genes associated with synaptic signalling, suggesting an inhibitory role for this miRNA cluster in neuronal development. Similarly, expression of miR-17~92 in the NB cell line SK-N-SH induces phenotypic changes in both morphology and proliferation. In this project, we are identifying the molecular mechanisms responsible for the inhibitory effects of the miR-17~92 cluster on neuronal development and synaptic signalling using single-cell profiling, direct miRNA target identification, and direct measurements of neuronal activity.