JARID2 is an integral subunit of the chromatin modifier PRC2 (Polycomb Repressive Complex 2). PRC2 methylates lysine 27 in histone H3 and is required for human development. Mutaitons of PRC2 subunits have been frequently found in a variety of adult and pediatric cancer, suggesting that PRC2 critically regulates normal and cancer development. The goal of this project is to identify new regulator or co-factors of PRC2 and study their molecular interactions and activities in order to better understand function and regulation of PRC2 in normal and cancer development.