The characterization of tumor molecular markers, along with the development of targeted therapies. Over half of these therapies can only be prescribed after determination of the status of a biomarker, rendering it necessary to carry out molecular tests. Recent technological advances enable us to simultaneously analyze numerous genes or portions of genes of interest by means of next-generation sequencing (NGS). Since January 2016, NGS has been applied in the Cliniques universitaires Saint-Luc (CUSL) as part of clinical routine analyzes related to diagnosis, prognosis, or therapeutic response prediction. At present, the panel used at CUSL allows mutations in different exons of eight genes (BRAF, c-Kit, EGFR, IDH1, IDH2, KRas, NRas, and PDGFRA) to be identified, such as those involved in metastatic colorectal cancers, non-small-cell lung cancers, melanomas, gliomas, and gastro-intestinal stromal tumors. This method has become an excellent diagnostic and prognostic tool, which also enables oncologists to individually determine the best treatment modality for each patient, with better chances of therapeutic success while diminishing unnecessary treatments.