Generation of MCA sarcoma cell lines of varying immunogenicities to study cancer immunoediting by innate and adaptive immunity. (A) The carcinogen MCA is administered to syngeneic mice with three levels of immune function. (n ≥ 20 mice for each cohort). (B) The immunogenicity of the MCA sarcomas is postulated to be heterogeneous. (C) MCA sarcoma cell lines are generated from each tumor mass and transplanted into syngeneic WT mice (n > 5 for each cell line) to assess growth. (D) Shown is the % growth of each cell line after transplant into WT mice. Cell lines that grow in <51% of the mice are termed regressors. Cell lines that grow in >50% of mice are termed progressors. (E) For each genotype, the percentage of tumor cell lines that displayed a regressor growth pattern is plotted. The “percent regressor tumors” is postulated to be inversely correlated with the quantity of immune pressure that is occurring during tumor formation in each mouse genotype.