AIM:Esophageal cancer remains a significant healthproblem worldwide.It is important to investigate alterationsin expression of retinoic acid receptor-β,p53 and Ki67proteins in esophageal caminogenesis.METHODS:To find biomarkers for early identification ofesophageal cancer,we analyzed the retinoic acid receptor-β,p53 protein and the proliferation marker Ki67 in surgicalspecimens of normal,mildly,and severely dysplastic andmalignant esophageal tissues by in situ hybridization ofRNA and immunohistochemistry.RESULTS:RAR-β was expressed in 94.3 %(33/35)of normalmucosae,67.8 %(19/28)of the mild,58.1%(18/31)of thesevere lesions and 53.2 %(116/218)of tumor samples.RAR-mRNA was expressed in 62.7 %(42/67),55.1%(43/78)and29.2 %(7/24)of well,moderated and poorly differentiatedSSCs.The p53 and Ki67 proteins were 5.9 %(2/34)of thenormal mucosa.P53 and Ki67 stained positively in 10.7 %(3/28)and 21.4 %(6/28)of mild dysplasia,and 51.6 %(16/31)and 58.1%(18/31)of severely dysplasia respectively.Samples from esophageal cancer showed no higher levers ofp53 and Ki67 expression than seen in severely dysplasticlesions.There was significant difference of RAR-β,p53 andKi67 expression between normal mucosa and dysplatictissue or esophageal cancer.CONCLUSION:Loss of Rar-βexpression abd accumulation of p53 and Ki67 proteins may serve as biomarkes for early identification of cancer in the high-risk populations. AIM: Esophageal cancer remains a significant health problem worldwide. It is important to investigate alterations in expression of retinoic acid receptor-β, p53 and Ki67 proteins in esophageal caminogenesis. METHODS: To find biomarkers for early identification of esophageal cancer, we analyzed the retinoic acid receptor-β , p53 protein and the proliferation marker Ki67 in surgical specimens of normal, mildly, and severely dysplastic andmalignant esophageal tissues by in situ hybridization of RNA and immunohistochemistry. RESULTS: RAR-β was expressed in 94.3% (33/35) of normalmucosae, 67.8% ( 58.1% (18/31) of these lesions and 53.2% (116/218) of tumor samples. RAR-mRNA was expressed in 62.7% (42/67), 55.1% (43/78) ) and29.2% (7/24) of well, moderated and poorly differentiatedSCs. The p53 and Ki67 proteins were 5.9% (2/34) of thenormal mucosa. P53 and Ki67 stained positively in 10.7% (3/28) and 21.4 % (6/28) of mild dysplasia, and 51.6% (16/31) and 58.1% (18/31) of severely dysplasia respectively.Sample s from esophageal cancer showed no higher levers of p53 and Ki67 expression than seen in severely dysplastic lesions. There was a significant difference of RAR-β, p53 and Ki67 expression between normal mucosa and dysplatictissue or esophageal cancer. CONCLUSION: Loss of Rar-βexpression abd accumulation of p53 and Ki67 proteins may serve as biomarkes for early identification of cancer in the high-risk populations.