RB1 and prostate intraepithelial neoplasia: However, two transgenic PC models with Akt activation plus Rb loss exhibited different metastasis development: Pten/RbPE:−/− mice produced systemic metastatic adenocarcinomas with high AKT2 activation, whereas RbPE:−/− mice deficient for the Src-scaffolding protein, Akap12, induced high-grade prostatic intraepithelial neoplasias and indolent lymph node disseminations, correlating with upregulated phosphotyrosyl PI3K-p85α.