The proliferation rate and clonogenicity of SW-684, SW-982, and SW-1353 ALDH1high cells in vitro were significantly higher than that of ALDH1low cells, consistent with the characteristics of the high ALDH1 activity phenotype in other cancer cells [33], [34], which may indicate that ALDH1high cells from sarcoma are partially responsible for tumor metastasis and recurrence and should be focused during the cancer therapy. This evidence concerns the gene ALDH1A1 and cancer.