However, the results from our preclinical murine study showed that MNC-QQ cell therapy directly accelerated wound closure, maturation, and vascularization in both diabetic and euglycemic wounds by upregulating matrix metalloproteinase-9 and transforming growth factor-beta gene expression.23 Finally, although mild and transient AEs were frequent, severe AEs or development of emboli, malignant tumors, or angina pectoris did not occur during our trial. Here, MMP9 is linked to cancer.