EGFR and fibrosarcoma: EGFR activation exerts its effects via the rat sarcoma (RAS)/rapidly accelerated fibrosarcoma (RAF)/mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) pathways [3].Mutation in the EGFR gene downstream signaling pathways may result in receptor-independent pathway activation, making tumors unresponsive to EGFR inhibitors.