While acknowledging the limitations of eGFR in patients with AKI, our findings are consistent with studies showing large numbers of terminally differentiated CD4 + T helper and CD8 + cytotoxic T cells in patients with ESRD52, and raise the ultimate question of whether or not these data may provide new targets for slowing or even preventing the progression from AKI to CKD in humans. This evidence concerns the gene CD4 and acute kidney injury.