CD9 and liver cancer: The lateral diffusion of CD9 on wild-type platelets (0.029 μm2/s) was substantially lower than previously reported for CD9 on PC3 and HeLa epithelial cancer cells (0.23 and 0.24 μm2/s, respectively) [43, 52], and for the related CD81 on HepG2 liver cancer cells (0.11 μm2/s on non-polarised and 0.07 μm2/s on polarised cells) [53].