ERBB4 and gastric cancer: Given that ErbB receptors, including ErbB1, ErbB2, ErbB3 and ErbB4 (also known as HER1, HER2, HER3 and HER4), are a group of receptor tyrosine kinases (RTKs) involved in key cellular functions such as cell growth, survival and metastasis during tumorigenesis including gastric cancer [33], we thus want to determine whether oncogenic role of AIB1 in gastric cancer is associated with the activation of ErbB receptors.