E2F1 and lung cancer: Indeed, previous functional studies have revealed that cis-acting genetic variation at a putative TP53 recognition site (for the rs2296147 T allele) and that an E2F1/YY1 response site (for the rs751402 A allele) is associated with higher levels of allele-specific ERCC5 transcripts in the normal human bronchial epithelium among lung cancer patients [51], which is in agreement with our current finding that the rs2296147 C allele may be protective against ESCC.