Characteristics of ATL cell–bearing NOG mice. (A) The macroscopic appearances of mice treated with vehicle (control; top panels) or BAY 1143572 (bottom panels). Tumor masses are demarcated by thin white dashed lines. (B) Photomicrographs of hematoxylin and eosin–stained liver sections from mice numbers 1, 5, 6, 7, and 8 treated by vehicle (control; top panels) or BAY 1143572 (bottom panels; scale bar, 500 μm). (C) The macroscopic appearance of ATL cell–bearing control mouse 6; i.p. tumor masses are demarcated by thin white dashed lines (left panel). Human CD45⁺ cells within masses were positive for CD4 and CD25, being consistent with ATL cells as determined by flow cytometry (the 2 right panels). SSC-H, side scatter height.