| EGFR Inhibitor Resistance Markers | ||||
|---|---|---|---|---|
| Marker | Name | Biological Role | Evidence | References |
| KRAS | v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog | GTPase that relays signals from membrane receptors to downstream effectors (e.g., RAF kinase) to regulate cell proliferation and survival | Activating mutations are correlated with resistance to cetuximab and erlotinib in colorectal and lung cancer | EGFR inhibitor resistance: KRAS mutation references |
| BRAF | v-raf murine sarcoma viral oncogene homolog B1 | Serine/threonine protein kinase that regulates MAPK-ERK signaling pathway | Activating mutations are correlated with resistance to cetuximab in colorectal cancer | EGFR inhibitor resistance: BRAF references |
| PTEN | Phosphatase and tensin homolog deleted on chromosome 10 | PIP3 phosphatase that is a tumor suppressor that reverses the action of PI3 kinase, thereby reducing the activation of AKT and downstream signaling | Loss of expression is correlated with resistance to cetuximab in colorectal cancers with WT KRAS | EGFR inhibitor resistance: PTEN references |
| PIK3CA | Phosphatidyl-inositol triphosphate kinase catalytic domain, alpha subunit | Phosphorylates the lipid PIP2 to form PIP3 which attracts signaling proteins to the membrane, where they activate downstream effectors, e.g., PDK and AKT | Activating mutations are associated with resistance to cetuximab in colorectal cancers with WT KRAS | EGFR inhibitor resistance: PIK3CA mutation references |
