The evidence for chicken genes, XP-C (Xeroderma pigmentosum group C-complementing protein) and RAD23B (UV excision repair protein RAD23 homolog B) is only at the transcriptional level. The predicted proteins share 50% homology with corresponding human proteins. The association of XP-C, RAD23B and the subsequent binding of the complex to damaged DNA sites where inferred from corresponding human reaction. However, evidence from studies using chicken cells suggest subsequent recruitments of repair proteins at the damaged DNA sites indicating an existence of Global Genomic Nucleotide Excision Repair in place.