The present invention provides inhibitors of thioredoxin reductase, in particular selenium compromised thioredoxin reductase-derived apoptotic protein (SecTRAP) forming agents, for use in treating an immune cell infiltrated cancer (e.g. a T-cell infiltrated cancer) in a subject, wherein said agents stimulate an anti-cancer immune response. The present invention also provides combinations comprising a SecTRAP forming agent and other therapeutic agents for use in treating cancer.