In agreement with the dispensable role for LPP in modifying primary tumour growth, NMuMG-ErbB2 cells expressing dox-inducible LPP shRNA formed mammary tumours that grew at similar rates when injected into doxycycline (LPP knockdown: LPP-shRNA, +Dox) or vehicle-treated (LPP proficient: LPP shRNA, −Dox) mice (Supplementary Fig. 9a). Here, ERBB2 is linked to breast cancer.