As shown in the upper panel of Figure 3A, the ovarian cancer cell lines (SKOV3, HEY, UCI101, A2780 and OVCAR3), the primary tissues cultures established from patients with stage III serous-papillary epithelial ovarian cancer (named tumor 1 with associated ascites 1 and tumor 2) and the primary tissue culture established from a benign ovarian tumor all expressed the OB-Rb isoform, as measured by conventional RT-PCR. Here, RB1 is linked to ovarian cancer.