he nine genes (Ubr1, Ptpns1, Ubce7ip5 and Mmp9; all of which are on MMU2) are of particular interest. It has been suggested the Socs2 may rely on ubiquitination dependent proteasomal degradation to inhibit Gh signaling [23]. Ubr1 and Ubce7ip5 are both involved in protein ubiquitination and Ubr