  The increasing observation of mutual exclusivity correlations among cancer
gene mutations is a key component for identifying driver events or pathways in
cancer genome analysis. Here we report a rigorous statistical method to compute
an exact $p$-value for the beyond-pairwise mutual exclusivity or co-occurrence
relationships among cancer gene mutations by enumerating a null distribution of
overlapping mutations across more than two genes. The validity and the
advantage of our method is explicitly demonstrated in both cancer gene
mutations and simulation data through the comparison to the permutation test.
