ALDH2 and breast cancer: Additionally, we demonstrated that CSCs, when engrafted orthotopically in the bladder, developed a phenotypically heterogeneous tumor resembling the clinical and histological features of primary invasive BC; under these conditions, a minority of cells expressing markers of undifferentiated cells including SOX2, ALDH2 and CD47, was observed, together with an expanded population of proliferating differentiated cells.