IRS1 and Insulin resistance: This pattern suggests that 10− 6 M insulin induces insulin resistance in human DPSCs, leading to impairments in proximal insulin signaling events (INSR, IGF1R, IRS1, and PI3K) while maintaining the activity of distal pathway components (AKT and mTOR), and 10− 6 M insulin continues to enhance DPSC proliferation and osteogenic differentiation.