Patients who are evaluated by the Pediatric Oncology Branch and are: Children with cancer (or a pre-cancer syndrome), between the age(s) of 3 months - 40 years who present with disease manifestations of special interest to Pediatric Oncology Branch investigators, because they are likely to shed led light on disease pathogenesis or the clinical behavior of the disorder. Patients between the ages of 30 and 40 years may be evaluated on this protocol if their cancer (or pre-cancer syndrome) is of specific interest to the Pediatric Oncology Branch.