RAC1 and neoplasm: These miRNAs have been implicated in pancreatic cancer progression through a variety of mechanisms, including negative regulation of tumor suppressor genes (e.g., miR-21-mediated downregulation of PTEN), underexpression of tumor suppressing miRNAs (e.g., miR-124 negative regulation of Rac1 oncogene), or cell cycle alteration resulting in enhanced proliferation (e.g., miR-203 downregulation inducing G1 phase progression) [12].