On the other hand, only the addition of testosterone (T) to these cultures could significantly increase the percentages of CD9-positive cells (premeiotic cells) and ACROSIN-positive cells (meiotic/post-meiotic cells) in vitro compared to BC, while addition of FSH did not affect the percentages of premeiotic or meiotic and post-meiotic cells in these cultures (Table 1). Here, CD9 is linked to breast cancer.