CD4 and neoplasm: Figure 6 shows the results of PRCC for each parameter in the model. We denote this PRCC by P^ for the combined treatment scenarios. For this case, the parameters have a strong relationship with the susceptible tumor size are decay rate of tumor-suppressing cytokines γc, with P^(γc)=0.6121, measure of CTLA-4-mediated inhibition on IFN-γ of CD4+ T cells by, with P^(by)=0.5760, tumor killing rate by cytokines δc, with P^(δc)=−0.5613, IFN-γ production rate of CD4+ T cells αy, with P^(αy)=−0.5270, and tumor growth rate ru, with P^(ru)=0.3875.