As mentioned earlier, gene expression alterations, e.g. loss of function mutations in TSGs and gainof-
function mutations in oncogenes are the most common hallmarks for malignant transformation of
the normal cellular tissue. Most often, such mutations result from chromosomal translocations or
deletions leading to fusion formation of two different gene transcripts and further altered and
modified gene expression. The most common recurrent disease specific chromosomal
rearrangements and gene fusions have been mainly found to be associated with hematologic
malignancies (lymphomas and leukemias) and sarcomas.