TGFB1 and cancer: The role of TGF-β in PAI-1 transcription was previously illustrated by Dennler et al (Dennler et al., 1998); however, just as Kirschbaum et al demonstrated liver regeneration via horizontal transfer of platelet mRNA to hepatocytes (Kirschbaum et al., 2015), horizontal transfer of PAI-1 mRNA to cancer cells from the platelets cannot be ruled out, and PAI-1 may serve as a transcription factor (TF) for itself in this scenario.