SNAI1 and cancer: Utilizing mice models overexpressing PAPP-A in the mammary gland in FVB/n background and xenograft mice models using MCF-7 and MCF-7 with overexpressed PAPP-A or KO PAPP-A, it is now known that PAPP-A transforms the anti-proliferative post-partum collagen into pro-tumorigenic collagen and elevates the well documented drivers of cancer progression and EMT, DDR2 and Snail [103].