ERBB2 and breast cancer: Furthermore, study by Foster et al. used XIAP siRNA to sensitize breast cancer cells to gefitinib treatment, and their work also suggested that inhibition of another ERBB family member, HER2, also can cooperate with XIAP siRNA59; as such, it will be informative to explore the role of both EGFR and other ERBB family members in synergistic responses.