The Atlas of Genetics and Cytogenetics in Oncology and Haematology, created in 1997 by Jean-Loup Huret (with bioinformatics by Philippe Dessen) is a collection of resources on genes, chromosomes anomalies, leukemias, solid tumours, and cancer-prone diseases. The project is accessible through Internet and is made of encyclopedic-style files, as well as traditional overviews, links towards websites and databases devoted to cancer and/or genetics, case reports in haematology. It also encompasses teaching items in various languages. The Atlas of Genetics and Cytogenetics in Oncology and Haematology, created in 1997 by Jean-Loup Huret (with bioinformatics by Philippe Dessen) is a collection of resources on genes, chromosomes anomalies, leukemias, solid tumours, and cancer-prone diseases. The project is accessible through Internet and is made of encyclopedic-style files, as well as traditional overviews, links towards websites and databases devoted to cancer and/or genetics, case reports in haematology. It also encompasses teaching items in various languages. Starting first from cytogenetics in the nineteens, the Atlas now combines different types of knowledge in a single web site: genes and their function, cell biology (ex: Apoptosis) , pathological data, diseases and their clinical implications, cytogenetics, but also medical genetics, with hereditary disorders associated with an increased risk of cancer. This gives a wider and more global view of cancer genetics, while these data are usually dispersed. More data is available from the site of the association in charge of the Atlas. . The Atlas is part of the genome project and participates in research on cancer epidemiology. The Atlas is accessed by: 1- researchers in cytogenetics, molecular biology, cell biology; 2- clinicians, haematologists, cytogeneticists, pathologists, from the university hospitals, indeed, but also from general hospitals where the Atlas is one of the rare free resources. Junior doctors in haematology or oncology, are also most receptive to the Atlas that they see as a training and educational tool; 3-Students in medicine and life sciences.