In breast cancer, knocked down KIF11 significantly reduces the level of cancer stem cell markers and number and size of breast cancers in vivo through inactivating the Wnt signaling pathway via inhibiting the nuclear translocation of β-catenin and downregulating the expression of transcription factor T-cell factor 1 (TCF1) and cyclin D1 (CCND1), the known downstream gene of this pathway [163]. The gene discussed is CCND1; the disease is cancer.