NCI is working with international laboratory collaborators in Canada, Germany, the Netherlands, and the United Kingdom to study diverse inherited bone marrow failure syndromes, to investigate human susceptibility to leukemia, head/neck cancers, and anogenital cancers. Investigators are engaged in gene mapping and sequencing and are studying a wide range of clinical, epidemiologic, genetic, behavioral, and laboratory features of these syndromes. These collaborations continue in an ad hoc fashion, as specific questions arise.