Gene expression in mouse and human LZ/DZ. (A) Unsupervised clustering of microarray data from LZ and DZ cells sorted from mouse lymph node or human tonsil. (B) Volcano plots showing global differences between naive and GC, plasma cell and GC, and LZ and DZ B cells in human and mouse. Microarray data for naive and total GC B cells and plasma cells data were obtained from Luckey et al³⁵  and Long et al.³⁶  Green lines indicate 2-fold differences (x-axis) and P = .05 (y-axis). Numbers in the plots indicate the number of probes differing by 2-fold or more (P < .05 in each of the comparisons). The total number of probes plotted for each species is indicated on the left.