Chemotherapeutics are still regarded as a mainstay of antitumor strategies. A number of observations indicate that these agents might be used at low doses with the same or even better efficacy than the high-dose chemotherapy. The efficacy of the low-dose chemotherapy might be at least partly explained by the regulation of the antitumor immune response. These immunomodulatory effects might be further potentiated by combinations with selected biological response modifiers, such as recombinant cytokines (IL-2, TNF, IL-12). The effectiveness of such combinations has already proved encouraging in pre-clinical models.