ERBB2 and breast cancer: Anti-HER2 immunoliposomes combine the tumor-targeting properties of mAbs, with the drug delivery properties and multi-drug resistance (MDR) mitigation ability of sterically stabilized liposomes encapsulating chemotherapeutic agents; offering prolonged inhibition of the HER2 pathway across multiple lines of treatment which will hopefully result in continued improvements in outcomes for HER2-positive breast cancer patients18,19,23.