CD4 and neoplasm: In contrast, the organ harboring dormant tumor cells had higher number of Tregs than the organ with actively growing tumor cells in the mouse B cell lymphoma model (BCL1), whereas, Tregs from both tumor microenvironments had similar capacities in suppressing the proliferation of CD4+ and CD8+ T cells suggesting the function of Tregs was not impaired by the induction of dormancy (57).