Given the association of DICER1 mutations with cERMS, de Kock and colleagues71 sought to evaluate the practical utility of DICER1 testing as an aid in the challenging differential diagnosis of uterine adenosarcoma; these authors assessed 19 cERMS and 27 uterine adenosarcomas with a consensus diagnosis, and found that 18 cases (95%) of cERMS had a DICER1 mutation compared to 7 cases (26%) of uterine adenosarcoma. The gene discussed is DICER1; the disease is uterine corpus adenosarcoma.