CDKN1A and neoplasm: Naïve MSCs can inhibit Wnt signalling pathways through modulating the Dickkopf-related protein 1 (DKK1) released by tumor cells, and subsequently downregulating c-Myc and Cyclin D2 and upregulated expression of P21CIP1 and P27KIP1, leading to tumor cells suppression [23–25].