In initial experiments we exploited the fact that MCF7 breast cancer cells lack endogenous nuclear Snai1 (Figure S1) and that introduction of Snai1 into these cells has been shown to repress E-cadherin luciferase reporter activity (Figure S2) [31], allowing for a clear link between the effects of the agent and the presence of its target. Here, SNAI1 is linked to breast cancer.