ERG and prostate carcinoma: In a previous study of patient-derived T:E-positive prostate cancer xenografts, Hermans et al. show that AR-positive and androgen-sensitive xenografts express high levels of T:E fusion transcripts, whereas some AR-negative and androgen-insensitive xenografts still express a basal level of ERG or no expression, and thus conclude that T:E fusion expression is functionally correlated with AR expression and its AR-dependent regulation may be bypassed in late-stage AR-negative prostate cancer [16].