Co-culture of CT26 cells and splenocytes extracted from CT26 tumor bearing mice and further in vitro uptake assay showed a significant 2-fold increase in uptake of [3H]DDG in splenocytes isolated from the mice treated with 4-1BB compared to untreated mice (p < 0.01 by t-test, Figure 5e). This evidence concerns the gene DDX53 and neoplasm.