Together with the association of lymph node metastasis, and the similarity between the tumor center and lymph node metastasis, it is plausible that ALDH1A1-expressing cells might play a role in invasion as suggested before in inflammatory breast cancer [65] or metastasis as suggested before in OSCC [66]. This evidence concerns the gene ALDH1A1 and metastatic malignant neoplasm in the lymph nodes.