NOTCH3 and Osteopenia: The purpose of the present work was to determine whether Notch3 could be downregulated in skeletal cells with a mouse specific Notch3 ASO and possibly ameliorate the osteopenia of Notch3em1Ecan mice, a mouse model of LMS and NOTCH3 gain-of-function secondary to the stabilization of the NOTCH3 NICD resulting in higher levels of NOTCH3 activity.