Tumors exist within a complex microenvironment that is influenced by the tumor and that affects the ability of the tumor to grow. Although a relationship between inflammation and cancer is known, the distinction between positive and negative effects of inflammatory-mediating white blood cells on tumor progression is unclear. Here, Mikala Egeblad, Andrew Ewald and colleagues describe a new system to visualize the dynamics of white blood cells in the tumor microenvironments of live mice. They use spinning disk confocal microscopy and illustrate distinct activities in different types of myeloid cells and find that location influences stromal cell movement.
