Intratumoral injection of adenovirus bearing the ATF2 peptide causes reduction of growth as well as complete regression of B16F10 tumors. C57BL/6 mice were injected with B16F10 cells, and tumors grew before injections of adenovirus bearing the ATF2 or control construct were initiated. Virus injection took place at the time points indicated in c (green arrows). (a) Representative tumors developed under each of the protocols. (b) The ATF2 peptide inhibited metastasis of the tumors. Green arrows point to metastatic lesions in the lungs seen in the control but not the treatment group; the black area in the photograph of ATF2 peptide–expressing mice depicts the heart. (c) Overall changes in the growth rate of the tumors subjected to control or ATF2 peptide treatments (compiled from the two experiments). Comparisons between all experimental groups are significant (P < 0.0001) as calculated by Tukey’s multiple comparisons (Tukey’s honestly significant difference). (d) The effect of ATF2 peptide on the survival of the mice under each of the protocols used.