PERP and breast carcinoma: Also notably, even though trastuzumab upregulated PERP, GNAS2, GNA13, RAB10, and ITB1 in EVs emitted by trastuzumab-sensitive breast cancer cells (Figs. 2, 3, and 4), the drug did not have this effect on all of these proteins in the cells themselves: trastuzumab downregulated ITB1, upregulated RAB10 and PERP, and had no effect on GNAS2 and GNA13 in the indicated cells (Fig. 6).