PTEN

phosphatase and tensin homolog - a tumor suppressor active in EGFR, HER2 and AKT cell signaling pathways. Cancers that may benefit from testing for this biomarker: breast, colon, lung (non-small cell), brain (glioblastoma), head and neck.

low expression associated with lack of response to cetuximab (Erbitux®), gefitinib (Iressa®), trastuzumab (Herceptin®), panitumumab (Vectibix®), erlotinib (Tarceva®)