Juxtaposed with another zinc finger protein 1 (JAZF1) also known as TAK1-interacting protein 27 (TIP27) or zinc finger protein 802 (ZNF802) is a protein that in humans is encoded by the JAZF1 gene. Translocations involving the region 7p15.1-p15.2 are frequently found in endometrial stromal sarcoma (ESS). The most common cytogenetic abnormality detected in 33-80% of ESS is t(7;17) (p15.1-p15.2;q11.2) which results in the fusion of the JAZF1 gene at 7p15.1-p15.2 to the JJAZ1 (Joined to JAZF1; a.k.a. SUZ12) gene at 17q11.2. Both genes involved contain zinc finger domains characteristic for DNA binding proteins. It was shown that the fusion protein JAZF1-JJAZ1 can promote cell proliferation when the wild-type JJAZ1 is silenced as it is in ESS harboring the t(7;17). In 25-30% of ESS the JAZF1 gene is disrupted by another translocation t(6;7) where the first zinc finger domain of JAZF1 is fused to both zinc finger domains of the PHF1 (PHD finger protein 1) gene at 6p21.32. As a result the entire coding region of PHF1 is regulated by the JAZF1 promoter. Since the diagnosis of ESS is often difficult in cases showing diverse histological differentiation or in undifferentiated endometrial sarcoma (UES), the detection of the JAZF1 translocations can serve as a diagnostic tool to confirm the diagnosis of ESS.