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. JAZF1 gene encodes a nuclear protein with three C2H2-type zinc fingers, and functions as a transcriptional repressor. Chromosomal aberrations involving this gene are associated with endometrial stromal tumors. JAZF1 has been identified at the breakpoints of a recurrent chromosomal translocation, the t(7;17)(p15;q21), in endometrial stromal tumors (benign nodules and sarcomas). The translocation leads to a JAZF1-JJAZ1 fusion gene. This gene fusion is detected in about 50% of endometrial stromal sarcomas and most endometrial stromal nodules. Another common chromosomal translocation in endometrial stroma sarcomas, the t(6;7)(p21;p15), results in a JAZF1-PHF1 fusion. About 25-30% of endometrial stromal sarcomas are reported to contain this fusion. The sites of fusion within JAZF1 RNA to JJAZ1 and PHF1 RNA sequence are the same.