YAP1 and breast cancer: LM2 cells harbour mutant KRAS (G13D),72 which activates the kinases MEK and ERK, driving proliferation and survival.73,74 However, while MEK inhibition (MEKi) effectively kills some cancer cells such as melanoma cells, breast cancer cells are often resistant to MEKi.75,76 Because MEKi resistance in melanoma, pancreatic and non-small lung cancer (NSLC) is often due to YAP/TAZ activation,25,26,77,78 we assessed whether the MEKi resistance of LM2 cells was due to DOCK5 and/or YAP/TAZ activity.