CPE and breast cancer: The position of the deletion in CPE-∆N and the primer sets used for PCR are shown in Figure 1C. As shown in Figure 1D, the amplified PCR region in exosomes derived from CAOV3 (ovarian cancer), HCC97H (liver cancer), and MDA-MB-231 (breast cancer) cell lines corresponds to WT-CPE gene segments, and not CPE-∆N.