(A) Flow cytometric analysis of the labeling of HL60 cells transfected with CB2 receptor cDNA (HL60-CB2) by anti-CB2 receptor Abs. After formaldehyde fixation and saponin permeabilization, HL60-CB2 (top histogram) and wild-type HL60 cells (bottom histogram) were labeled with anti-CB2 receptor Abs preincubated (dotted line) or not (solid line) with the C-terminal peptide of the CB2 receptor. (B) Confocal microscopic analysis of the localization of CB2 receptors in HL60-CB2 cells. The left side corresponds to HL60-CB2 stained with anti-CB2 receptor Abs and the right side corresponds to HL60-CB2 stained with anti-CB2 receptor Abs preincubated with the C-terminal peptide as negative control.