ERBB receptors including EGFR, HER2 and HER3 are critical single pass transmembrane protein which are crucial player in different cancer progression. For example HER2 is overexpressed in approximately 20 % cases of breast cancer and associated with poor survivol to patients afflcted with this form of cancer. HER2 and EGFR also mutated most frequently in breast and lung cancer cases. Here in meilerlab we apply different methods of computational chemistry and biology in collaboration with cancer biologist to understand the detail mechnism of these form of breast and lung cancer cases. We strucutually identify the most malignant mutants and their activation mechanism which is very important for devising effective targetted therapies for this form of cancers.