IDO1 and Alzheimer disease: Therefore, to examine the effect of this interaction, BM-MSCs, AD-MSCs, DP-MSCs and UC-MSCs were pre-conditioned with 1000 ng/ml, 2000 ng/ml, and 3000 ng/ml of Dex for 24 h and 48 h and then, PGE-2, IDO and HLA-G1/G5 were assessed at both gene level and protein level.