DICER1 and neoplasm: In contrast, another study reported that in the Dicer1 flox/flox Pten flox/flox Amhr2cre/+ ovarian cancer GEMM, treatment with progesterone (P4) alone significantly accelerated tumor development and progression in all ovariectomized Dicer1-Pten double-knockout (DKO) mice, whereas the addition of combined estrogen and progesterone treatment inhibited this rapid progression [9].