$$\begin{array}{rcl}\frac{d{X}_{2}}{dt} & = & \mathop{\underbrace{{r}_{p2}\,{X}_{2}}}\limits_{{\rm{proliferation}}}\mathop{\underbrace{-{\mu }_{2}\,{X}_{2}}}\limits_{{\rm{death}}}\mathop{\underbrace{+{r}_{M}\mathrm{(1}-A)\,{X}_{1}}}\limits_{mutation...