Although there was no difference between the high expression of USP9X in normal mucosa and low grade intraepithelial neoplasia (P = 0.369), nor between high grade intraepithelial neoplasia and ESCC (p = 0.115), significance was detected in USP9X expression between low grade intraepithelial neoplasia and high grade intraepithelial neoplasia (p = 0.012). This evidence concerns the gene USP9X and esophageal squamous cell carcinoma.