Umbilical cord-derived mesenchymal stem cell transplantation for COVID-19 patients: long-term benefits for lung regeneration. Biomed. Res. Ther. [Internet]. 2022 Feb. 28 [cited 2024 Nov. 15];9(2):4950-2. Available from: https://preservation.bmrat.org/index.php/BMRAT/article/view/725