Exosomes have been utilized as a potential therapeutic tool including the natural exosomes, exosomes with modifications, and exosomes loaded with exogenous cargo.53 Naturally secreting exosomes derived from lung spheroid cells (LSC-Exo) have recently been reported to promote lung repair in pulmonary fibrosis through inhalation.54 As ACE2 is a key regulator of lung pathology and protect the lung from injury, our results may partially explain the mechanism that LSC-Exo promotes the lung repair. The gene discussed is ACE2; the disease is pulmonary fibrosis.