evidence: mRNA cancer vaccines mRNA-based cancer vaccines have been recently and extensively reviewed115,116,117,118,119. Below, the most recent advances and directions are highlighted. Cancer vaccines and other immunotherapies represent promising alternative strategies to treat malignancies. Cancer vaccines can be designed to target tumour-associated antigens that are preferentially expressed in cancerous cells, for example, growth-associated factors, or antigens that are unique to malignant cells owing to somatic mutation120. These neoantigens, or the neoepitopes within them, have been deployed as mRNA vaccine targets in humans121 (Box 2). Most cancer vaccines are therapeutic, rather than prophylactic, and seek to stimulate cell-mediated responses, such as those from CTLs, that are capable of clearing or reducing tumour burden122. The first proof-of-concept studies that not only proposed the idea of RNA cancer vaccines but also provided evidence of the feasibility of this approach were published more than two decades ago123,124. Since then, numerous preclinical and clinical studies have demonstrated the viability of mRNA vaccines to combat cancer (Table 3).