Successful engraftment and massive infiltration of primary ATL cells into various organs of NOG mice inoculated with PBMCs from patients with ATL. (A) Photographs of whole organs of normal and ATL cell-challenged mice with enlarged spleen, liver, and lungs (left 2 panels). Right 2 panels show May-Grunwald and Giemsa staining of PBMCs collected from normal and ATL cell-challenged mice, 2 months after inoculation of ATL cells, respectively. (B) HE (top) and immunohistochemical staining of various organs of NOG mice inoculated with ATL cells. Immunohistochemical staining using anti-CD4 (middle) and anti-CD25 (bottom) was conducted on various organs of mice tissues 2 months after inoculation of ATL cells. Magnification ×40.