TCGA accrued samples for all of these tumor types simultaneously. As samples became available, the tumor types with the most samples accrued were entered into production. For more rare tumor types, tumor types where samples are difficult to accrue and for tumor types where TCGA cannot identify a source of high quality samples, these types of cancer entered the “TCGA production pipeline” in the second year of the project. This gave the TCGA Program Office additional time to accrue sufficient samples for the project.