The excision repair cross-complementation group 1 (ERCC1) gene encodes a protein required for nucleotide excision repair and inter-strand crosslink repair of DNA (1). While DNA-damaging chemotherapeutic drugs like cisplatin are commonly used for non-small cell lung carcinoma and other late-stage tumors, these drugs have a high degree of resistance and severe side effects (1,3). Platinum chemotherapy drug resistance has been linked to elevated levels of ERCC1-XPF nuclease, therefore making ERCC1 a potential predictive diagnostic biomarker (2,3). ERCC1 expression may have prognostic value in lung, colorectal, head and neck, bladder, breast and cervical cancers (1-7).
Although clone 8F1 has traditionally been used in immunohistochemistry to detect ERCC1 expression, 8F1 has been found to cross-react with PCYT1A, an unrelated nuclear membrane protein. Clone 4F9 does not show this cross-reaction, providing superior specificity for ERCC1 expression (2-4).