MKI67 and esophageal squamous cell carcinoma: Caprin-1 expression in ESCC patients was significantly associated with lymph node metastasis (P = 0.031), Ki-67 expression (P = 0.023), SUVmax (P = 0.002), and SUVmean (P = 0.005), but not with gender, age, tumor size, differential status, p stage, TLG or MTV.