Two structurally distinct calcilytics NPS2143 and Calhex 231 were shown to suppress excessive cell proliferation of IPAH-PASMCs, but not in normal or CTEPH (chronic thromboembolic pulmonary hypertension) PASMCs, whereas R568, an activator of CaSR, significantly enhanced the proliferation of IPAH-PASMCs (Yamamura et al., 2015). The gene discussed is CASR; the disease is chronic thromboembolic pulmonary hypertension.