Following the establishment of two different xenograft models (B16F10 melanoma and LL/2 Lewis lung carcinoma) in mice, inducible ablation of ERK5 in a mouse model carrying an Mx1-Cre transgene resulted in the regression of the tumor vasculature and a concomitant reduction in tumor volume by 63% and 72%, respectively. This evidence concerns the gene MAPK7 and neoplasm.