Recombinant IL-2 protein has shown many immunostimulatory effects in a variety of human tumors. However, the clinical use of rIL-2 is limited by common and serious side effects after systemic administration. IL-2 expression plasmids may circumvent these drawbacks, producing high local IL-2 concentrations that cause limited or no systemic side effects. Due to the superficial growth of squamous cell carcinoma of the head and neck (HNSCC) are readily accessible for direct intratumoral injection and therefore an optimal target for such a gene therapy approach. There has been evidence for local and systemic activation of immune cells by peritumoral injections of IL-2 in patients with advanced HNSCC. We now perform a placebo-controlled, dose-rising study of the safety and tolerability of a single intratumoral injection of hIL-2 plasmid at four dose levels formulated in DOTMA/Chol in patients with primary untreated head and neck squamous cell cancer (HNSCC) TNM stage II-IV. The patients will be monitored for the occurrence of any adverse reactions to the given medication. In addition, we will determine whether the intratumoral administration of the plasmid induces and or enhances tumor-specific host responses at the immunological and or clinical level.