(A), Immunohistochemical determination of CD133 expression. The CD133 antibody stained intensely at the membrane and in the cytoplasm of cancer cells. Scores were applied as follows: 0, negative staining in all cells; 1+, weakly positive or focally positive staining in <10% of cells; 2+, moderately positive-staining in 10%-50% of cells; and score 3+, strongly positive-staining, involving 50% or more of the cells. (B), Immunohistochemical determination of ALDH1 expression. The ALDH1 antibody stained intensely at the membrane and in the cytoplasm of cancer cells. Scores were applied as follows: 0, negative staining in all cells; 1+, weakly positive or focally positive staining in <10% of cells; 2+, moderately positive-staining in 10%-50% of cells; and score 3+, strongly positive-staining, involving 50% or more of the cells.