Fig. 3: Immune escape occurs early and increases the risk of tumor formation.

a Comparison of the adenoma (CRA) founder’s immune escape phenotype to the eventual founding branch of the carcinoma (CRC) population, where GL = founder relied on Get Lucky, B = founder had Blockade, S = founder had Suppression, and SB =  founder had Suppression and Blockade. Out of the 21,723 simulations, 75.87% of the simulations had the acquisition of Suppression as an early event, occurring in the CRA founder and later inherited by the CRC founder. b The probability of a carcinoma forming under various strengths of immune escape. Probability is calculated as the number of times a carcinoma existed for 1 year, divided by the number of times that parameter set was run, in this case, 100 times each. The gradient from left to right indicates that immune suppression increases the probability of tumor formation, while lack of a gradient from top to bottom suggests that immune blockade has little effect on the probability. c The average amount of time, in days, between CRA and CRC formation, i.e., the transition time, for each parameter set. Tumors that progressed most rapidly from CRA to CRC are those with an immunosuppressive strategy, which reduces immune predation and relaxes selection against high antigenicity. d Averages of each malignant tumor’s mean antigenicity (weighted by each population’s size) for each parameter combination. The horizontal gradient indicates that immune suppression allows for increased antigenicity, as immune suppression relaxes selection against immunogenicity.