Analysis of OS in subgroups stratified according to tumor localization in the biopsy cohort also revealed a significant association of aberrant p53 with decreased OS only in distally (p log rank = 0.04) located tumors but not in those located in the middle (p log rank = 0.47) and proximal (p log rank = 0.58) third (data not shown). The gene discussed is TP53; the disease is neoplasm.