ERBB2 and breast cancer: In breast cancer, functional up-regulation of expression of human epidermal growth factor receptor 2 (HER2), a ligand-independent receptor tyrosine kinase (RTK), can arrest the expression of RAC-alpha serine/threonine-protein kinase (AKT1) (a key factor in the mTOR pathway), which is reported to inhibit the activation of cGAS and TBK1 (244, 245).