ITGB4 and breast carcinoma: Palmitoylation of integrin subunits beta-4 (ITGB4), alpha-3 (ITGA3), and alpha-6 (ITGA6) impacts on the formation of integrin tetraspanin complexes.100 ITGA6 and ITGB4 cooperate with EGFR and ERBB2 to facilitate multiple aspects of tumor progression and metastasis.101 For example, in a mouse model of ERBB2-mediated breast cancer, ITGB4 forms a complex with ERBB2 and amplifies ERBB2 signaling.