EWSR1 and acute leukemia: This aspect and its consequent limit on the availability of adequate material for additional molecular diagnostics are probably the main reasons why only very few studies on genomic EWS-FLI1 fusion sequences are published, in contrast to numerous studies on EWS-FLI1 transcripts and genomic breakpoints in fusion genes in diseases with more freely available material, e.g., acute leukemia [13], [26].