"Although studies addressing their role in cancer pathogenesis are at an early stage, it is apparent that specific microRNAs (miRs) and molecules involved in their biogenesis contribute to tumorigenesis. The ONCOMIRS consortium proposes a natural succession of four experimental strategies. Fist, we will DISCOVER and unveil novel miRs and components of their biogenesis machinery and investigate links between these molecules and human cancers. Secondly, we will CONNECT the information obtained on deregulated miRs with known cellular pathways involved in cancer, such as the p53 tumour suppressor pathway. This will be conducted using both forward experimentations, in which targets mRNA are experimentally identified for a number of miR aetiologically related to cancer, and reverse experimentations in which mouse models and cell lines with abrogated tumour suppressor pathways or activated oncogenes are used. To establish a causal relationship between dysregualted miRs and cancer development we will MODEL the tumorigenic processes in mice lacking or overexpressing particular miRs. Finally, since the specificity and potency of some miRs suggest that they might be promising as THERAPEUTIC agents, these models will be used in conjunction with other cancer models to explore miR-based therapeutic strategies."