CD8A and neoplasm: Reduced expression of cluster of differentiation (CD) 133 and cyclo‐oxygenase (COX) 2, and increased density of CD8+ intraepithelial tumour‐infiltrating lymphocytes (TILs) in biopsy specimens obtained from colonoscopy before preoperative CRT, have been reported to be predictive markers of good tumour response8, 9.