CD9 and cancer: Also, considering that the growth and malignancy of SH-SY5Y cells45 and HT2946 cells are reportedly related to the sEV release process, the different effects of the cell cycle on CD63+ and CD9+ sEV release observed in these cell lines raise a question about how cell-cycle-inhibiting anti-cancer drugs might influence the release of a specific subpopulation of sEVs that affects cancer malignancy (note that we also observed a difference between cell types: halting the cell cycle of SH-SY5Y and HT29 cells increased the release of CD63+ sEVs (Fig. 5f)).