PCNA and neoplasm: Interestingly, the G-MSC secretome down-regulated the expression of genes associated with proliferation and anti-apoptosis activity, such as p-ERK1/2, Bcl-2, CDK4, Cyclin D1, STAT3, PCNA and survivin, and the ERK signalling pathways; it also up-regulated the JNK cascade and expression of pro-apoptotic genes, including JNK, cleaved PARP, and cleaved caspase-3, which negatively regulated the cell cycle and tumour proliferation and increased angiogenesis.