In another study, Cai et al. [43] also show that ERG is expressed at comparable levels in T:E-positive androgen-dependent primary prostate cancer and androgen-independent CRPC; and in T:E-positive VCaP xenografts, its levels shows initial down-regulation in castrated mice but returns to precastration levels in relapse tumors. The gene discussed is ERG; the disease is prostate cancer.