NR1D1 and Right ventricular hypertrophy: Similarly, in mice with CIH-induced PH, inhibition of Nr1d1 expression significantly alleviated CIH-induced remodeling and muscularization of peripheral pulmonary arteries, elevated RVSP, and right ventricular hypertrophy, thereby retarding the progression of CIH-induced PH in mice (Fig. 2H–N).