ERBB4 and neoplasm: Similarly, as the third-generation EGFR TKI, pyrotinib covalently binds to ATP binding sites in intracellular kinase regions of EGFR, HER2 and HER4, preventing homodimer formation, thereby irreversibly inhibiting autophosphorylation, blocking activation of downstream signaling pathways, and inhibiting tumor cell growth.156–158 It received conditional marketing approval from the National Medical Products Administration (NMPA) in August 2018.