Members of the TGF-β superfamily (TGF-β1/2/3, GDF-5, and GDF-6) can all promote MSC differentiation towards NP-like cells, with GDF-6 having a particularly significant effect, inducing richer proteoglycan ECM synthesis, and showing more pronounced effects in AD-MSCs compared to BMSCs (Stoyanov et al., 2011; Tao et al., 2015; Clarke et al., 2014; Colombier et al., 2016; Gantenbein-Ritter et al., 2011). Here, TGFB1 is linked to Alzheimer disease.