This is an open-label follow up study to evaluate the safety for the subjects with ALLO-ASC-DFU treatment in phase 1 clinical trial (ALLO-ASC-DFU-101) for 23 months.

This is an open-label follow up study to evaluate the safety for the subjects with ALLO-ASC-DFU treatment in phase 1 clinical trial (ALLO-ASC-DFU-101) for 23 months.

ALLO-ASC-DFU is a hydrogel sheet containing allogenic adipose-derived mesenchymal stem cells. Adipose-derived stem cells have anti-inflammatory effect and release growth factors such as vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF), which can enhance wound healing and regeneration of new tissue, finally may provide a new option in treating a Diabetic Foot Ulcer.

Inclusion Criteria:

1. Subjects who are treated with ALLO-ASC-DFU sheet in phase 1 clinical trial of ALLO-ASC-DFU-101.
2. Subjects who are able to give written informed consent prior to study start and to comply with the study requirements.

Exclusion Criteria:

1. Subjects who are considered not suitable for the study by the principal investigator (For example, Subjects requiring surgical procedure on target site).

Subject is enrolled who are treated with ALLO-ASC-DFU sheet in phase 1 clinical trial of ALLO-ASC-DFU-101.