In recent years, gene mutations in the PI3/AKT/mTOR pathway have been detected from the affected lesions of vascular anomalies (vascular tumors and malformations) with development of genetic analysis technology. It is related with the pathogenesis of the disease and has led to development of targeted therapies, such as mTOR inhibitors, sirolimus. Sirolimus has shown high efficacy in treating lymphatic disorders and received approval in September 2021. It is anticipated that personalized medicine based on genetic analysis and targeted therapies will continue to advance in the future.