IDO2 and periodontitis: MSCs isolated from inflamed tissue showed a diminished immunosuppressive capacity in vitro: DPSCs from irreversible pulpitis had a significantly reduced ability to suppress T-cell proliferation and lower indoleamine 2,3-dioxygenase activity compared to healthy pulp DPSCs, and similarly, periodontitis-derived PDLSCs exhibited a weaker capacity to modulate immune cell activity than their healthy counterparts [33, 66].