Probable proto-oncogene that functions in the epidermal growth factor receptor/EGFR signaling pathway. Activates both RAS/MAPK and PI3K/AKT/TOR signaling cascades downstream of EGFR. Required for the RAS/MAPK signaling cascade activation upon EGFR stimulation, it also activates both signaling cascades independently of EGFR activation. Interacts with the regulatory subunit p85 of PI3-kinase; increased by EGFR activation. Interacts with RAF1; increased by EGFR activation it activates RAF1. Phosphorylated upon EGFR activation. Belongs to the FAM83 family.