Reduced expressions of Id-1 and Id-3 have been demonstrated to inhibit the metastatic ability of gastric cancer cells (Tsuchiya et al, 2005), and Id-1 expression has been shown to be associated with the presence of invasion in endometrial carcinoma (Takai et al, 2001) and tumour angiogenesis in human pancreatic cancer (Lee et al, 2004). Here, ID3 is linked to gastric cancer.