CSCs/CICs could be identified from urothelial carcinoma samples using several methods including the use of cell surface marker CD44+ or 67-kDa laminin receptor, side population analysis using Hoechst 33342 or Dye-cycle violet, and ALDH1 activity based on the ALDEFLUOR assay [4–8]. This evidence concerns the gene ALDH1A1 and urothelial carcinoma.