Csnk2b also directly interacts with Shmt1, which has enhanced transcription of 3.5-fold (Fig. 3) , and has been further confirmed in DIGE experiments (Egger et al., unpublished) . The third Wnt pathway mentioned is the Wnt/Ca 2+ pathway which includes, among others, Plc (Plcb1 5-fold increase on the microarray), CaMKII (4-fold decrease on the microarray) and Calpain (3-fold decrease on the microarray). Our mapping of genes differentially transcribed with c-secretase activity shows that they encode proteins that directly interact with each other, with many of them being members of Wnt pathways.