Provided are methods for inhibiting cancer cell growth comprising contacting the cancer cell with an agent which inhibits the expression of the gene, or the activity of, apolipoprotein B editing catalytic 3G (APOBEC3G). Also provided are methods for identifying agents which can induce or inhibit C>；U deamination in RNA driven by apolipoprotein B editing catalytic proteins. The method comprises contacting APOBEC3G with a suitable RNA substrate and determining the extent of C>；U deamination under conditions which induce APOBEC driven C>；U deamination.
