ERG and Ewing sarcoma: The TMPRSS2 gene encodes a cell‐surface proteinase (transmembrane serine protease 2, TMPRSS2) and is located at chromosomal locus 21q22.3 in close proximity to ERG, a gene encoding an ETS transcription factor (Link to UniProt, Paoloni‐Giacobino et al., 1997) (ERG fusion with EWS leads to Ewing's sarcoma).