Figure 1. High expression of Btk in human ovarian tumors is associated with a poor cancer prognosis.

(A)Immunohistochemistry staining was performed to identify the expression of Btk in ovarian cancer tissue microarrays. Representative images of immunostained tissues from different stages of ovarian cancer patients and benign ovarian patients are presented. (B) Three ovarian tissue specimens were randomly selected and subjected to microdissection to separate the tumor and nontumor parts. The expression of Btk was assessed using western blotting. Our data showed that the expression of Btk in tumor samples was consistently higher in the tumor parts than in surrounding nontumor parts. (C) Immunohistochemically stained malignant samples were categorized into two groups and compared with the overall survival rate. (D) The Kaplan–Meier graph was consistent with survival data from the PrognoScan database, revealing that the expression of Btk is correlated with lower overall survival.