ERG and prostate cancer: The most common chromosomal rearrangement in prostate cancer results in the fusion of the androgen-regulated gene, TMPRSS2 (chr21q22.2), with ETS-related gene, ERG (chr21q22.3), which is present in approximately 50% of patients [9]; due to the high incidence of prostate cancer, this is the most prevalent fusion gene in human cancer [10].