IFNG and neoplasm: Another study has shown that ICAM-1 is exclusively expressed in aggressive tumor cells linked to the development of tertiary lymphoid structures (TLS) such as triple negative breast cancer (TNBC) and HER2 (human epidermal growth factor receptor 2), and that an encouraged ICAM-1's expression, in a number of cell lines, was observed by the pro-inflammatory cytokines TNFα, IL-1β (interleukin 1β) and IFNγ [24].