The analysis of two identified studies supports our observations: in the data of Grasso et al. [36]ERG was the topmost gene co expressed with TDRD1. In the data of Taylor et al. [17], TDRD1 was found to be co expressed with ERG (r2 = 0.55) but not with ETV1 (r2 = 0.02) across 149 primary prostate tumors. The gene discussed is ETV1; the disease is prostate neoplasm.