Moreover, knockdown of FZD7 decreased the expression of the stem cell genes Nanog and Oct-4, the multidrug resistance transporter protein gene ABCG2, and the tumor stem cell-associated surface antigens CD133, CD44, and CD24, indicating that FZD7 possibly involved in the regulation of gastric cancer stem cell function and drug resistance (46). Here, POU5F1 is linked to gastric cancer.