qPCR verification of CFS tumor suppressor gene loss in PEL. (A-E) The qPCR results for DERL1, FHIT, GRID2, WWOX, and KSHV, respectively, are shown. Shown is the stacked relative level (ddCT) for each gene on the vertical axis and the 2 classes of 13 non-PEL (other) and 13 PEL cell lines on the horizontal axis. The contribution of individual cell lines is indicated by the gray level. Because amplifications and deletions result in only a 2-fold change in signal in the case of cellular genes (and ∼ 50-fold for KSHV because there are ∼ 50 copies of the KSHV genome in each PEL cell) the stacked representation integrates both the degree of change as well as the number of cell lines that contribute to the signal in each group (a similar metric was previously validated).³⁹