Treatments targeting PD-L1 were a breakthrough for cancer immunotherapy, however, are only applicable to inflamed tumors. Most tumors are not inflamed, and instead are poorly infiltrated by immune effector cells. Drug discovery aimed at increasing immune infiltration requires physiologically relevant models of the tumor microenvironment (TME); this poses a significant technological challenge: how do we model poorly infiltrated TMEs when we do not understand the underlying mechanisms suppressing infiltration? Instead of a traditional, biochemically-defined system, we are attempting to induce formation of an immune-excluded TME by co-culturing TME cell types in 3D culture, mimicking their in vivo orientation. To this end, we developed a protocol for in vitro generated cancer associated fibroblasts (gCAFs) by culturing fibroblasts (FBs) in conditioned medium (CM) from cancer cells. gCAFs have upregulated expression of extracellular matrix (ECM) genes and downregulated expression of immune cell attracting chemokines, as suspected of in vivo CAFs. The generation of a high-throughput, human 3D culture model of poorly immune infiltrated TMEs will enable identification of new drug targets broadly applicable to solid tumors and high-throughput screens for drugs that increase immune infiltration.