PCNA and cancer: The results show that proteins such as PCNA, cyclin D1, Bcl-2, MMP2, MMP9, and Bcl-xL, expressed in abundance in cancer cells, were significantly downregulated in WHCO1 and MDA MB 231 cells after treatment with MSC-CM, coculture with MSCs, or when grown on fd-ECM for 24 hrs (Figures 1(a)-1(b), densitometric analysis in Supplemental Figure S3 B-C).