Tunicamycin (TCM) stimulates phospho-PERK expression, but soluble Aβ does not. A) Mϕs were treated 18 h with TCM or soluble Aβ, and the expression of phospho-PERK in Mϕs was determined by immunofluorescence and scanning. B) Immunofluorescence of phospho-PERK in Mϕs of patient 12 on no treatment and after TCM treatment. Repeated measures ANOVA: no treatment vs. TCM, P = 0.08; no treatment vs. Aβ, P = 0.83. MFI, mean fluorescence intensity.