It is intriguing to point out that in the control Ig–treated mice, in which MB49luc bladder tumor burdens increased during the 72–144-h time interval, CD4+ and CD8+ effector T cell numbers (Fig. 2d, e) actually increased, yet their activation status fell (Fig. 5a and b), providing additional evidence for immunosuppression. This evidence concerns the gene CD4 and urinary bladder neoplasm.