ASXL2 is a human homolog of the Drosophila asx gene. Drosophila asx is an enhancer of trithorax (see MIM 159555) and polycomb (see MIM 610231) (ETP) gene that encodes a chromatin protein with dual functions in transcriptional activation and silencing (Katoh and Katoh, 2003 [PubMed 12888926]).[supplied by OMIM, Sep 2009]