Objective      To investigate the expression and clinical significances of the candidate tumor suppressor gene

opioid binding protein/cell adhesion molecule-like (OPCML) gene in human breast cancer tissues.       Methods      Immunohistochemical assay was used to detect the expression of OPCML in 117 tissue samples of breast cancer

41 samples of adjacent tissue and 24 samples of normal breast tissue. The results were analyzed with clinical data.       Results      The positive rate of OPCML was 19.66%（23/117）

90.24%（37/41） and 70.83%（1

7/24） respectively in the breast cancer

adjacent tissue and normal breast tissue

with that in the breast cancer significantly lower than those in the other 2 tissues (

P

0.05). Significant correlations were found in the expression of OPCML with histological grade

pTNM staging and lymph node metastasis of breast carcinoma (

P

0.05). Significantly negative correlations were seen among the expression of OPCML with that of Ki-67 (r=-0.261

P

0.05)

HER-2 (r=-0.294

P

0.05) and GFR (r=-0.242

P

0.05) respectively.       Conclusion      The candidate tumor suppressor gene OPCML is mildly expressed or deleted in the breast cancer

and its expression is negatively correlated with the expression of Ki-67

HER-2 and EGFR. It might play a role as suppressor gene in the development of breast cancer.