TGFB1 and Alzheimer disease: This study had two main goals: to test whether the stimulation of AD-MSC increased extracellular proteoglycan production and collagen type I using 3D culture in the presence or absence of TGFβ; and to examine the influence of AD-MSC on annulus cells by testing for a synergistic effect on proteoglycan production by 3D co-culture.