KLK6 and KLK7 genes and proteins are overexpressed in epithelia but absent in stroma of ovarian tumors. (A) To detect mRNA in tissues, serous ovarian tumors (S) and normal tissues (N) were hybridized in situ with KLK6 and KLK7 oligonucleotide probes followed by visualization of red chromogen staining by bright field microscopy under 10 × magnification. (B) To detect KLK6 and KLK7 protein expression in tissues, subtypes of ovarian tumors (S = Serous, PS = Papillary Serous, E = Endometrioid) and normal ovary tissues (N) either in whole mount sections or tissue arrays were analyzed with IHC. DAB staining was visualized by brightfield microscopy. (C) Detection of KLK6 and KLK7 protein levels in serous carcinomas by immunohistochemistry, observed under 40 × magnification that allows visualization of nuclear staining, which is indicated by a solid arrow. Cytoplasmic staining is indicated by a dotted arrow.