French teams gathered in the French Society of Paediatric Oncology and the European consortium "Innovative Therapies in Children with Cancer (ITCC)" decided a few years ago to perform biopsies of these tumours for diagnostic confirmation and to ensure the presence of certain therapeutic targets prior to a possible inclusion in a trial evaluating a targeted therapy (Geoerger, 2009; Geoerger, 2010). Part of this experiment was reported by the team of the Necker Hospital in Paris, confirming the low rate of complications of stereotactic biopsy procedure (Roujeau, 2007). The biopsy specimen analysis allowed practicing immunohistochemical, genomic (CGHarray), gene expression (transcriptome) and direct sequencing of candidate genes studies.