CD44 and ovarian carcinoma: In our previous studies, the CD44+CD117+double positive cell population in the SKOV3 cell line was only around 3.1–4.2 % [9, 11], and we think that the CD44+CD117+double positive cell population in ovarian cancer tiuuses from the CD44+CD117+ CSC immunized mice was significantly decreased compared with the mice immunized with other SKOV3 cell vaccine .