BRAF and colorectal cancer: The overrepresentation of additional Ras pathway driver mutations in colorectal cancers with class 3 BRAF mutations was very strong relative to class 1 BRAF-mutant colorectal cancers (45.7% vs. 2.40%; P < 0.001, Fisher exact test), and a slightly weaker association was present in class 2–mutant tumors relative to class 1 (29.0% vs. 2.40%; P < 0.001, Fisher exact test).