This CSV file provides a comprehensive mapping of identifiers for the TCGA TPM Expression Summary dataset, covering transcriptomic data from 10 cancer types. Each row links the original Legacy ID in "TCGA TPM Expression Summary: Processed Transcriptomic Data from 10 Cancer Types" to its corresponding UUID, Entity ID, Case ID, Sample ID, and Cancer Type. This mapping facilitates cross-referencing between legacy and current identifiers for downstream analyses and integration with other TCGA datasets.