Localization of fAPP695 in PC12 cells after treatment with NGF. PC12 cells stably expressing fAPP695wt (a, d), fAPP695T668A (b, e), and fAPP695T668E (c, f) were treated with NGF for 72 hr and double-stained with M2 (FLAG) (a–c) and T-3526 (tubulin) (d–f) antibodies. Scale bar, 25 μm.