These immunohistochemical findings indicate that endogenous MDR1 expression is associated with CDX2 expression in human ovarian cancer tissue as well as mucinous ovarian cancer tissues (P < 0.001; in human ovarian cancer, and P < 0.05; in mucinous ovarian cancer, using Fisher's exact test) (Tables S1, S2). The gene discussed is ABCB1; the disease is ovarian cancer.