The Cover:Confocal micrograph showing pericytes on a blood vessel in Lewis lung carcinoma stained for alpha-smooth muscle actin-immunoreactive pericytes (red) and CD31-immunoreactive endothelial cells (green). Pericytes on the tumor vessel are abnormally loosely associated with endothelial cells and have cytoplasmic processes that project into the tumor parenchyma.(see page 985).