Table 1. Notation and baseline parameter values.

Symbol	Baseline	Description
$b$ , $d$	1 , 0.1	Birth and death rates of a cancer cell
$\lambda$	1 , 10	Mean number of exomic mutations acquired per division per daughter cell
$p_a$	0.075	Probability of a mutation being antigenic (rather than neutral)
$p_e$	10–6	Probability of escape of an antigenic cancer cell into neutrality
$C_i$		Population of cancer cells carrying antigenic mutation $i$ , with total cancer cell population size $C$
$E_i$		Population of effector cells of type $i$ , with total effector cell population $E$
$B$ , $D$	0.2 , 0.1	Passive recruitment and per-capita death of an effector cell
${\alpha }_i$ , ${\beta }_i$ , ${\gamma }_i$	—-, —-, 10–3	Active recruitment, killing and inhibition/exhaustion rates, respectively, for interactions between cancer and effector cells of type $i$
$A_i$ , $I_i$		Antigenicity and immunogenicity, respectively, of antigenic mutation $i$ (each drawn from $\text{Exp}(1)$), with averages over the effector population $⟨A⟩$ and $⟨I⟩$
$S_j$		Site frequency: number of antigenic mutations occurring $j$ times
$B_k$		Single-cell mutational burden: number of cancer cells with $k$ antigenic mutations
$M_{a,\ell },M_{n,\ell }$		Set of antigenic and neutral mutations, respectively, carried by a cancer cell $\ell$
$M_a,M_n$		Total number of all antigenic and neutral mutations: $M_a=|{\bigcup }_{\ell }{M}_{a,\ell }|$ and $M_n=|{\bigcup }_{\ell }{M}_{n,\ell }|$
$U$		Total antigenic mutational occurrences: $U={\sum }_{j=1}^{C}j{S}_j={\sum }_{k=1}^{M_a}k{B}_k$
$K$	3 × 104	Ending cancer population size for stochastic simulations
$T_{\text{end}}$	16	Maximum time for a simulation