Cancer thrives by preventing the <strong>immune system</strong>  from targeting tumor cells. While current immunotherapies use dendritic cells to activate T-cells towards specific tumor antigens, they remain expensive and of variable efficiency against tumor immunosuppressive environment. To develop <strong>personalized therapies</strong>, our team focused on engineering yeast <em>Saccharomyces cerevisiae</em> for targeted immunotherapy. First, we developed a <strong>software to select the best tumor antigen</strong> from patient sequencing data. Second, we created a <strong>yeast chassis</strong> to prime the immune system with the targeted antigen. This chassis was tested <em>in vitro</em> on mouse splenocytes and <em>in vivo</em> on mice presenting melanoma with significant results. Three complementary strategies were combined to improve the chassis efficiency. First, in order to modulate the <strong>tumor environment</strong>, yeast secreting the specific immune modulator IFNgamma was encapsulated into alginate beads to be injected in tumors. Secondly, to <strong>break the immune tolerance</strong> against cancer cells, T4 and T8 lymphocytes were elicited by a yeast antigen display system that can be adapted to any tumor antigen for personalized therapy. Last, to <strong>deliver cytotoxic compounds</strong> solely in the tumor environment, a yeast hypoxia bio-sensor was designed. A side project consisted in engineering <em>Escherichia coli</em> to drive MAIT lymphocytes against cancer cells instead of their original targets, parasitized cells. Our <strong>standardized</strong> and <strong>customizable</strong> chassis takes advantage of these approaches to make personalized medicine a reality, with a scalable cancer therapy.</p>