Human β-cells did not increase DNA damage labeling after proliferative stimulation. Dispersed human islet cells were cultured for 96 h in the described conditions, with BrdU included in the culture media for the entire 96 h. Human insulin(+) cells cultured in 15 mmol/L glucose showed a trend toward modestly increased BrdU incorporation (A) but did not increase γH2AX labeling (B) or BrdU-γH2AX double labeling (C). Adenoviral overexpression of human cyclin D2 in 5 mmol/L glucose increased the BrdU labeling fraction (D) but not the γH2AX-labeling fraction (E); double-labeled cells trended upward (F). Combining glucose and cyclin D2 proliferative stimuli did not further increase BrdU (G), γH2AX (H), or double-labeled nuclei (I). Adeno-cre was used as a control for Adeno-cyclin D2, at the same multiplicity of infection. *P < 0.05. Adeno, adenovirus; gluc, glucose; Obs, observed; Predict, predicted.