To investigate specific roles for platelet miRNAs in primary solid tumor growth in vivo, we implanted “KPC” murine pancreatic carcinoma cells into the flanks of Dicer1fl/fl/Pf4-Cre C57Bl/6 mice, which are depleted of miRNAs specifically in megakaryocytes/platelets due to selective Dicer1 deletion in megakaryocytes, or Pf4-Cre C57Bl/6 control mice [52]. This evidence concerns the gene DICER1 and exocrine pancreatic carcinoma.