AKT1 and Alzheimer disease: This pathway-level analysis also identified signalling pathways involved in apoptosis and cell cycle regulation as being widely dysregulated in severely affected regions of AD brain, including the HIPPO, ERK/MAPK, PI3K/AKT and Wnt/β-catenin pathways (Figs. 3 and 4), all known to be critically involved in regulation of apoptosis and the cell cycle.