Chimeric antigen receptor (CAR) T-cell therapy involves the ex vivo transduction of a patient’s T cells with a CAR that recognizes a defined tumour antigen. While CAR T cells targeting hematologic malignancies have met early success in the clinic, the translation of these effects in solid tumour settings has proved to be much more difficult. This is due to additional barriers and immunosuppressive environment that solid tumour create to prevent CAR-T infiltration and function. Establishing models that brecapitulate the immunosuppressive microenvironment is critical to engineer armoured CAR-T cell products that can overcome these challenges.