PGR and breast cancer: While no statistically significant changes were noted in the levels of Dicer, levels of Ago2 were significantly up-regulated in the PFC tissues of untreated PR+BC TumorGraft animals (p = 0.0010) and in PR+BC/TOP and PR+BC/CRIZ (p = 0.00005 and p = 0.0020, respectively) (Figure 6).