Ki-ras mutations are found in approximately 90% of pancreatic adenocarcinomas and 40% of colorectal adenocarcinomas (Bos et al, 1987; Almoguera et al, 1988; Bos, 1989) These mutations convert the ras protein to a constitutively active protein, resulting in stimulation of cell proliferation. The gene discussed is KRAS; the disease is colorectal adenocarcinoma.