The biophysical properties of the tumor stroma have recently emerged as an important modulator of tumor progression, either by directly influencing the motility and invasiveness of tumor cells or by limiting the infiltration of T cells. T cells can recognize antigens expressed by tumor cells, consequently being activated and killing the tumor cells. Indeed, T cell-based immunotherapy is one of the latest breakthroughs in the treatment of cancer. However, the success of T cell-based immunotherapy is mainly limited to hematopoietic tumors. In solid tumors, the extracellular matrix surrounds the malignant cells, preventing T cells from accessing and killing the tumor cells. The requirements and properties of the tumor-associated extracellular matrix for efficient T cell infiltration are poorly studied. Here, we plan to combine our expertise in the tumor microenvironment and in T cells to investigate how the biophysical properties of the tumor-associated stroma influence T cell motility and infiltration within solid tumors.