PER1 and pancreatic neoplasm: We found that, in WT mice, but not FoxP1SkmKO mice, pancreatic cancer caused a substantial disruption to the gene expression of core clock components, including repression of Bmal1, which is part of the activating arm of the clock, and activation of Per1, Cry1, and Cry2, which are part of the repressive arm of the clock (Figure 2).