Upon flow cytometric enumeration, it was observed that the percentage of TPH2-positive cells has increased significantly only in BM-MSC (from 5.04 ± 0.37% to 9.62 ± 0.5580%); while it decreased significantly in AD-MSCs (from 12.46 ± 1.349% to 7.040 ± 0.81%) and DP-MSCs (from 12.28 ± 0.73% to 6.16 ± 0.57%). Here, TPH2 is linked to Alzheimer disease.