Circadian oscillations of circulating leukocytes in NSG and humanized mice. Blood samples were taken from 10-week-old NSG and humanized mice every 6 hours (ZT1-ZT25) and analyzed for the number of leukocytes (n = 6). The cell counts of each point in individual mice were normalized to the initial cell count at 0 hours (ZT1). Shown are fold changes of cell counts of NSG mCD45⁺ cells (A), NSG mGr-1⁺ cells (B), NSG F4/80⁺ cells (C), humanized mice mCD45⁺ cells (D), humanized mice hCD45⁺ cells (E), humanized mice hCD3⁺ cells (F), humanized mice hCD19⁺ cells (G), and humanized mice hCD3⁻CD19⁻ cells at different points against ZT1 (H). *P < .05; **P < .01.