AGO2 and breast cancer: Interestingly, 77 genes transcriptionally regulated by ERβ and harboring both ERβ and AGO2 binding sites within the transcription unit underwent an inversion of the ERβ-induced transcriptional trend following AGO2 silencing (Additional file 12: Table S9d), demonstrating a role of the functional interaction between these two factors on ERβ-mediated transcriptional regulation in BC cells upon physical association of the two proteins within the transcription unit (TU).