CD9 and neoplasm: Furthermore, loss of CD9 has been correlated with a higher motility and metastatic potential of the following tumour cells: lung (Higashiyama et al, 1995; Funakoshi et al, 2003; Wang et al, 2005), oral (Kusukawa et al, 2001), oesophageal (Uchida et al, 1999), ovarian (Houle et al, 2002), cervical (Sauer et al, 2003), and gastric (Murayama et al, 2002).