Fig. 3.

Transition therapy. Targeting proliferation of a single phenotype in a switching tumor (a). In the presence of PHS strategies, the resistant population $r_1$ is able to maintain tumor growth. Targeting sensitive cell death ($d_2$, b) or inhibiting transitions toward resistance ($w_{21}$, (c)) is likely to fail provided resistant cells replicate faster than they transition into the sensitive phenotype ($r_1>w_{12}$). PHS modeling indicates that only therapies draining $c_1$ into $c_2$ are effective across the whole parameter space (d)