Co-suppression of ID1 and ID3 significantly reduces proliferation, invasiveness, anchorage-independent growth, and angiogenesis and increases apoptosis in small-cell lung cancer (Chen D. et al., 2014); moreover, targeting ID1 and ID3 reduces the formation of peritoneal metastases by gastric cancer cells (Tsuchiya et al., 2005). Here, ID3 is linked to small cell lung carcinoma.