To their deep dismay, researchers discovered several years ago that laboratory samples of anaplastic thyroid cancer they were using to help them find new treatments for this lethal disease were probably some other kind of cancer. It quickly became evident that the situation in their lab was common throughout the world. Up to half of the cell lines that were supposed to originate from patients with this rare thyroid cancer were either colon or melanoma cancer. So, with the cooperation of many researchers nationwide, the researchers set out to create a new set of laboratory ATC cells, derived from tumors donated by patients.