PCA of all samples differentiates US and S samples only in UM-CLL and Mr-CLL (M responder CLL) cells. PCA of all 48 samples (24 M-CLL and 24 UM-CLL) and color-coded according to the legend, projected onto the first 2 principal components. Ellipses highlight M-CLL samples (US and S samples indiscriminately), US UM-and Mr-CLL samples except at time 1 hour, S UM- and Mr-CLL samples except at 1 hour, and UM- and Mr-CLL samples at 1 hour (US and S undiscriminated). PCA analysis demonstrated that M-CLL and UM-CLL cells formed 2 distinct groups and that US and S samples at 2, 4, and 7 hours can be differentiated only in UM-CLL and Mr-CLL samples.