Methods of treatment or prevention of a cancerous or pre-cancerous condition, of slowing or preventing growth of a cancerous condition, of stimulating a cell-mediated immune response, stimulating a Th1 helper T cell response against a pathogen in a mammal and of treating or preventing inflammatory diseases or disorders that involve administration of N-methyl pyrrolidone (NMP) or a physiologically acceptable salt, solvate, tautomer or prodrug thereof are provided. Also provided are formulations of an active agent.