A recent study reported a patient carrying biallelic EIF2AK4 gene mutation displayed good response to PAH-targeted therapy and was alive for over 3 years [26], similarly, all our patients were detected with biallelic EIF2AK4 mutations and showed good responses, but the prognoses of patients with biallelic mutations in EIF2AK4 varied [29], indicating possibly favorable effects of PAH-targeted drugs in patients harboring specific EIF2AK4 gene mutations. The gene discussed is EIF2AK4; the disease is pulmonary arterial hypertension.