BRAF inhibition trims the hairy projections of HCL but not HCL-like cells. Confocal immunofluorescence staining for phalloidin (green), annexin V (red) and Draq5 (blue) in primary leukemic cells purified from the blood of a representative HCL patient (no. 17, top panels) and a representative HCL-like patient (no. 2, bottom panels) and treated in vitro with vehicle (DMSO) or vemurafenib 1 µM (for 48 and 72 hours in the HCL and HCL-like patient, respectively). (A-B) Two-dimensional (2D) images of a representative field (×63 optical magnification with oil immersion). (C-D) Electronically magnified 2D-image of a representative cell for each condition.