CCND1 and neoplasm: The subsequent challenge of immunized mice with BCL1 tumor cells resulted in a reduction in the number of Tregs in the spleen, i. e. spleens from mice with both dormant and actively growing tumor had fewer Tregs (4.2 x 106 cells, p < 0.07 and 3.2 x 106 cells, p = 0.0002, respectively) than mice that were immunized but not injected with tumor cells (6.5x106 cells) (Fig 2B).