Knockdown of κ-OR in macrophages not only aggravated hypoxia-induced pulmonary vascular remodeling and right ventricular hypertrophy and decreased cardiac function but also aggravated the infiltration and inflammatory response of M1 macrophages around pulmonary vessels, which aggravated PASMC proliferation and HPH progression. The gene discussed is OPRK1; the disease is Right ventricular hypertrophy.