CCND1 and pancreatic neoplasm: To study underlying molecular mechanisms by which Six1 promotes cell growth of pancreatic cancer cells, we analyzed several cell cycle regulators and found that cyclin D1 protein levels were significantly higher in PANC-1 and MIA PaCa-2 cells transduced with Six1, whereas the cells with Six1 knockdown showed a reduced cyclin D1 expression (Figure 3A and Figure S1A).