Recently, Oliva et al. [27] reported that although only 1 of 10 cases of endometrial stromal tumors were CD10-positive, four out of four high-grade ESSs in the study by Agoff et al. [28] and four of six high-grade ESSs in the study by McCluggage et al. [9], were CD10-negative, indicated that in high-grade ESS, decreased expression may be related to tumor differentiation. The gene discussed is MME; the disease is neoplasm.