The EGFR/CEN7 probe is located on chromosome 7. A 520 Kb probe covering the EGFR gene region at 7p11.2 is labeled with an orange dye, and part of chromosome 7 (CEN7) is labeled with a green dye.

NSCLC patients (about 80% of lung cancers) with EGFR gene amplification show significantly improved treatment outcomes with tyrosine kinase inhibitors (TKIs). Used to screen NSCLC patients suitable for TKI therapy. EGFR gene amplification can also occur in various tumors including lung cancer, head and neck cancer, ovarian cancer, cervical cancer, bladder cancer, and esophageal cancer.