CD9 and cancer: Second, the number of CD9-GFP-loaded N-ALE per cell almost doubled for cancer cells (from 0.26 ± 0.05 to 0.48 ± 0.06 [106 cells] and 0.39 ± 0.07 to 0.59 ± 0.07 [113 cells] for FEMX-I and MDA cells, respectively), but not for MSCs (0.275 ± 0.06 to 0.34 ± 0.07 [62 cells]).