Fig. 5. In AD, PTEN overexpression decreases the protective effect of IGF-I. Serum-deprived SHEP/PTP (A), SHEP/wtPTEN (B), SHEP/C124S (C), and SHEP/G129E (D) cells are exposed to DMEM (D) + 10 nM IGF-I (I) or 300 mM mannitol (H) + 10 nM IGF-I for 24 h, followed by flow cytometry analysis as described in Fig. 1 . * = P < 0.01 compared with SHEP/PTP cells. ** = P < 0.01 compared with the corresponding condition without IGF-I.