TGFB1 and breast cancer: While further work is necessary to elucidate the cellular biochemistry of these signaling events and the molecular determinants within PEAK1 that are essential to facilitate TGFβ-induced MAPK activation in this context, it is useful to consider how antagonists of PEAK1 (e.g., CPX) can be leveraged in combination with existing therapeutic interventions in breast cancer (e.g., Src kinase inhibition) to combat this class of malignancies.