In this article we have shown that finding groups from BLAST reports can be reduced to computing maximal cliques in so-called c-max-tolerance graphs. We have presented two algorithms that allow the enumeration of all maximal cliques in c-max-tolerance graphs in polynomial time. The first algorithm has an easy implementation to compute all maximal cliques in c-max-tolerance graphs, but it has a theoretical runtime of O(n6). The second algorithm is technically very elaborate, and shows that enumeration of all maximal cliques in c-max-tolerance graphs can be computed in a runtime of O(n2 log n + out), where out denotes the size of the output. The algorithm improves a result found for general max-tolerance graphs, for which the computation of all maximal cliques has a runtime of O(n3) [9].