CD8A and type 1 diabetes mellitus: In a later trial, low-dose IL-2 was combined with polyclonal Treg adoptive therapy based on the assumption that IL-2 would expand the exogenously administered Treg cells; however, the investigators disclosed that in addition to an augmented Treg frequency, cytotoxic CD8 T cells were also substantially increased, calling for caution in the use of exogenous IL-2 in T1D [48].