NME1 and neoplasm: We also found that let-7b could inhibit the proliferation, and enhance the apoptosis, of human tumor cells by inhibiting the PI3K/Akt and MAPK signaling pathways and by activating the proapoptotic protein Bax and antimetastatic protein nm-23, both of which are involved in P450 epoxygenase- and EET-mediated tumorigenesis and metastasis [10].