ERBB2 and cancer: Given the relative paucity of mechanistic knowledge relating specific drug substructures to ADRs we carried out a detailed chemical dissection of mubritinib, which was reported to act as a tyrosine kinase (HER2) inhibitor and which has been trialled as a treatment for a range of cancers (Nagasawa et al., 2006; Ouchida et al., 2018).