TK1 and ovarian neoplasm: Furthermore, strong staining of TK1 in the cytoplasm (score > 50%) was also observed in the area with poorly differentiated ovarian cancer tumour tissue (grade 3), but little staining was observed in tissue far distant from the ovarian tumour tissue (score < 5%), confirming that hTK1-IgY-rmAb#5 is highly specific and sufficiently sensitive.