In vitro experiments demonstrated enhanced cytotoxicity induced by anti‐HER2‐coated immunoliposomes, which was attributed to augmented cellular uptake mediated by HER2‐binding.[157] In another study, anti‐HER2‐coated PEGylated immunoliposomes were compared with unmodified liposomes for delivery of PTX to HER2‐positive breast cancer in a mouse model. This evidence concerns the gene ERBB2 and breast cancer.