CD44 and prostate carcinoma: Indeed, selecting prostate cancer cells for TF-Ag expression resulted in the enrichment of cells with stem-like properties characterizing self-renewal capacity such as enhanced clonogenic survival and growth (Figure 3A–3E) and prostasphere formation under both non-differentiating and differentiating conditions (Figures 3F–3L), as well as increased expression of stem cell markers CD44 and CD133 (Figure 3M).