ERBB2 and neoplasm: However, this mechanism is subverted in trastuzumab-resistant cells, leading to αVβ6-independent and HER2-independent tumor progression (Fig. 7B), whereby GDI2 is depleted from the αVβ6-proximal adhesome and invasion is unaffected by αVβ6, HER2, or TGFβ inhibition (Fig. 7B).