ERBB2 and neoplasm: Although ERBB2 is over-expressed in progressive and metastatic PTC cases (Kremser et al., 2003), and high expression of ERBB2 was found to be responsible for resistance to mitogen-activated extracellular signal-regulated kinase inhibitors (MEKi) (Montero-Conde et al., 2013), the ERBB2 upregulation-related unfavorable phenotypes, such as tumor occurrence, proliferation, metastasis, and poor progression-free interval (PFI), have not been comprehensively explored in PTC, and the relations between ERBB2 expression and the immune microenvironment in PTC remains unknown.