NME1 and neoplasm: Some tumor-associated stromal cells can produce tumor suppressor factors, such as nucleoside NME1 (Dooley et al., 1994), Kangai 1 (KAI1/CD82) (Dong et al., 1997) and IL-25 (Furuta et al., 2011), in the tumor microenvironment, and these activities can restrict the development or metastasis of surrounding tumor cells.