Improved patient survival is linked to increased immune cell infiltration into tumors, which also predicts response to immune therapies. In order to develop strategies to intervene on these targets, it is essential to identify the factors that influence the degree of immune infiltration. T cells enter tumor tissues through the vasculature and are controlled by interactions between tumor vascular endothelium and tumor cell nests and homing receptor ligands( HRLs ). There may also be active barriers to infiltration, and HRLs are frequently lacking in tumors. These are still unresearched, but they could be essential for improving immune-mediated cancer control. Numerous intratumoral and systemic therapeutic strategies, including both approved and experimental therapies, have the potential to improve T cell infiltration. This review focuses on the intracellular and extracellular factors that contribute to immune cell infiltration into tumors, as well as obstacles to it and strategies for enhancing it.