The tumor microenvironment (TME) is comprised of an array of cell types, including immune and inflammatory cells, adipose cells, neuroendocrine cells, and cancer-associated fibroblasts. Additionally, blood and lymphatic vascular networks and extracellular matrix components create a diverse and multifaceted situation. Understanding how all of these elements interact requires the ability to distinguish individual cell types--something that is difficult to do using bulk cell approaches. Single cell gene expression analyses offer a high-resolution understanding of the TME.