['The aim of the present study was to investigate the prognostic value of B-cell associated protein 31 (BAP31) in human primary hepatocellular carcinoma (HCC).', 'BAP31 levels were evaluated by immunohistochemistry on tissue microarrays. The integral optical density, representing the expression level of BAP31 in each tissue sample, was calculated with image-pro plus. Immunohistochemical analysis of BAP31 levels in 74 paired HCC tissues and peritumoral non-cancerous tissues showed that BAP31 expression was significantly higher in HCC tumour tissues (P = 0.025). The prognostic value of BAP31 in HCC was evaluated in 234 cases in a training cohort and in 63 cases in a validation cohort. The expression level of BAP31 was significantly correlated with overall survival (OS) in both the training cohort and the validation cohort. The lower the level of BAP31 expression in HCC tissue, the poorer the prognosis. Univariate and multivariate analyses showed that the expression level of BAP31 in HCC was an independent prognostic factor for OS in both the training cohort and the validation cohort.'] Does low expression of B-cell-associated protein 31 in human primary hepatocellular carcinoma correlate with poor prognosis?