Over the past years, the MSCs infusion exhibited an excellent safety record as evident in the 871 clinical trials registered in the National Institute of Health database (https://clinicaltrials.gov/ct2/results?cond=Mesenchymal+Stem+Cells&term=&cntry=&state=&city=&dist=), including 117 trials (https://clinicaltrials.gov/ct2/results?cond=mesenchymal+stem+cell&term=pulmonary&cntry=&state=&city=&dist=&Search=Search) on pulmonary complications, to date.