CTL019 results in B-cell depletion in primary and secondary lymphoid tissues. Sections of bone marrow, spleen, lymph nodes, terminal ileum, and colon, obtained at autopsy from a CTL019-treated subject (day 234), were analyzed by H&E and IHC (CD20, κ, λ). Representative sections are shown at ×20 (all spleen and CD20 images) and ×40 magnification (all other images). H&E insets are shown at ×100 magnification.