TGFB1 and cancer: Platelets also contribute to extravasation by promoting an invasive mesenchymal-like phenotype in cancer cells through direct platelet-cancer cell interactions and through the release of TGFβ (Labelle et al., 2011), or by releasing ATP-containing granules that modulate the endothelial lining and cause vascular leakiness (Schumacher et al., 2013).