GDF6 and Alzheimer disease: The differentiated AD-MSCs show an increase in aggrecan-to-type II collagen gene expression.155 GDF-6 also has the potential to enhance ECM accumulation and induce cell migration in certain disc cells.156 Miyazaki et al. found that the expression of TNF-α, IL-6, VEGF, COX-2, and NGF was significantly reduced by injecting GDF-6 into a rabbit puncture model of IVD.