SPINK1 and ovarian carcinoma: For ovarian cancer, use of SPINK1 as a biomarker may be best accomplished through staining of larger tumor sections, as one limitation of our study was the use of TMAs to detect SPINK1 protein expression, where the heterogeneous expression of SPINK1 in ovarian tumors may have led to false negatives (SPINK1 expression missed due to inadequate tumor sampling).