Jpbrody at en.wikipedia [Public domain] from Wikimedia CommonsDecades of cancer research have shown that development of most tumors requires a combination of several genetic mutations. A wide array of such combinations has been implicated in tumorigenesis, and determining which combinations are the most troublesome has been tedious. Now a new mouse model seems poised to facilitate more rapid testing of mutation combinations and hence to accelerate the identification of those with the greatest oncogenic potential.