(A) Photomicrograph of LGL in PB of Tg-mice injected with 500 ng of hGM-CSF twice a day for 1 week. This smear preparation was stained with May-Grünwald-Giemsa. (B) Dose-response relationship between hGM-CSF injected and the generation of LGL in PB. Tg-mice and normal littermates (N-mice) were injected with serum/PBS or 100 to 2,500 ng of hGM-CSF twice daily for 1 week, and the proportion to lymphocytes and absolute number of LGL was evaluated on day 8.