Predicted to enable phosphatidylinositol 3-kinase inhibitor activity. Predicted to be involved in early endosome to late endosome transport and negative regulation of phosphatidylinositol 3-kinase/protein kinase B signal transduction. Is an ortholog of C. elegans sorf-1. In C. elegans, sorf-1 is involved in organelle fusion and positive regulation of early endosome to late endosome transport.