The biology of atherosclerosis initiation, progression, and complications. This figure illustrates some of the important targets for molecular imaging that are discussed in the text. CCR2, chemokine (CC motif) receptor 2; MCP, monocyte chemoattractant protein; M-CSF, monocyte colony-stimulating factor; MMP, matrix metalloproteinase; ROS, reactive oxygen species; VCAM, vascular cell adhesion molecule. (Reprinted with permission from Libby P. Inflammation in atherosclerosis. Nature 2002;6917:868–74.)