JAZF1 and endometrioid stromal sarcoma: Chromosome abnormalities involving polycomb proteins have been frequently detected in human endometrial stromal sarcoma (ESS) patients, In low grade ESS, the most frequent genetic rearrangement is the t(7;17)(p15;q21) [52], which results in genetic fusion of JAZF1 and SUZ12, which was originally referred to as JJAZ1.