CDKN1B and esophageal squamous cell carcinoma: Positive rate of p27 protein expression was 0% (0/5) in esophageal adenocarcinoma (ESAC) and 80% (4/5) in paired normal esophagus tissues, 0% (0/26) in esophageal squamous carcinoma (ESCC) and 26.9% (7/26) in paired normal esophagus tissues, 3% (1/32) in GC and 37.5% (12/32) in paired normal gastric tissues, 10% (3/30) in CRC and 50% (15/30) in paired normal colorectal cancer (Figure 2).