TMPRSS2 and prostate cancer: Oncogenic fusions include aberrations that join a strong promoter that drives overexpression and a second proto-oncogene (e.g., TRABD–DDR2),41 leading to downstream deregulation.42,43 Additionally, fusions affecting transcription factors are important oncogenic drivers.44 Examples include PML-RARα fusions in leukemia,45ETS gene fusions and TMPRSS2-ERG fusions in prostate cancer,10,46 and the PAX3-FOXO1 fusion in alveolar rhabdomyosarcoma, a pediatric cancer.47 Transcription factor aberrations are promising drug targets in cancer and have been reviewed previously.44