they indicate activation of residual cancer that is then therapeutically controlled by androgen deprivation. However, disseminated cancer cells often become androgen-independent, leading to another increase in circulating PSA levels and manifesting metastases. From the observation of the latter rise in PSA level to the appearance of symptomatic metastases, the disease does not exert symptoms affecting physical wellbeing. For this reason, no therapy is administered, lest the quality of life be adversely affected by chemotherapy that is currently used in terminal PCa. Thus, the period of asymptomatic PSA level increase has been considered appropriate for studies testing the efficacy of immunotherapy that is usually devoid of major adverse events. PCa immunotherapy has begun to yield encouraging clinical effects, though not a definitive cure. For example, partial responses have been Methoxsalen induced by autologous transfer of ex vivo activated antigen presenting cells, cytokine-secreting tumor vaccines, vaccines containing recombinant proteins or nucleic acids and other cell-based strategies targeting cancer antigens, such as PSA or prostate-specific membrane antigen. Most recently, a treatment employing ex vivo processed autologous antigen presenting cells combined with prostatic acid Ginsenoside-Rb2 phosphatase has received regulatory approval for treatment of metastatic PCa. In a recent phase 2 clinical study, an allogeneic PCa wholecell vaccine stimulated expansion of tumor-specific immune cells in non-metastatic androgen-independent PCa patients. The treatment was safe, and the rate of PSA increase was reduced in 11 out of the 26 studied patients. Yet, the patients demonstrated a significant variability in response to treatment, that could be due to differences in individual immune history and tumor biology. Suppressed immunity in PCa patients could also contribute to the relative lack of efficacy of PCa immunotherapy. Restoring and enhancing immunity should be a major goal of immunotherapy, yet the complexity of immune system defies the attempts to achieve it. For that reason, immunity has been often studied by mathematical modeling. Mathematical modeling has been a valuable tool in describing, quantifying and predicting the behavior of complex systems. In particular, mathematical models have played an important role in providing non-intuitive insights into tumor growth and progression, tumor-associated angiogenesis, and evolution of drug resistance. Mathematical models have been successfully validated and applied for rational design of cancer therapy, for optimizing efficacy while minimizing toxicity, and for streamlining drug discovery and development. More recently, cytokine-based and cellular immunotherapy have been modeled and scrutinized, and some models were validated experimentally and clinically.