IGF1 and Alzheimer disease: In comparison with non-dementia controls, down-regulation of IGF1 in AD was also observed in training sets (Figure 4(e)), including GSE5281 (AD: 4.76 ± 1.27 vs. controls: 6.63 ± 0.90; p < 0.001) and GSE37264 (AD: 5.04 ± 1.07 vs. controls: 5.99 ± 0.54; p = 0.04).