To assess whether the reduction in growth in soft agar observed with the oncogenic HRASG12V-transformed KrasC118S/C118S MEFs reflected a defect in the more relevant in vivo phenotype of tumor growth, these cells and the control oncogenic HRASG12V-transformed Kras+/+ MEFs were injected into the flanks of five immuno-compromised mice each, after which tumor growth was monitored over time. This evidence concerns the gene KRAS and neoplasm.