TMPRSS2 and cancer: However, samples of 17 triplets were found more frequently in the TMPRSS2:ERG fusion positive than negative tumors and mediated a higher rate of androgen-induced TMPRSS2 and ERG colocalisation than AR with longer (24) and shorter (15) CAG repeats, suggesting that 17 triplets were associated with TMPRSS2:ERG fusion positive cancer.