Western blot analysis revealed that DPP-4 knockdown increased the levels of the autophagosome marker LC3II and decreased the expression of the autophagy substrate p62 in the human MCF7 and MDA-MB-231 breast cancer cell lines and mouse 4T1 mammary cancer cells (Figure 1A), suggesting autophagic induction by DPP-4 suppression. This evidence concerns the gene DPP4 and breast cancer.