APP and neuroblastoma: In SH-SY5Y human neuroblastoma cells, sAPPα, a soluble amyloid precursor protein (APP) fragment secreted in conditioned medium of cultured cells, human plasma, and the cerebrospinal fluid, could modulate the expression of RACK1 and the signaling activity of PKCβII through the activation of the PI3K/Akt and NF-κB pathways.