Across TCGA pan-cancer cohorts, TNN mass-spec protein differs between tumor and matched normal tissue in 4 of 18 cancer types tested, making tumor–normal expression one of TNN’s most consistent transcriptional readouts.
The strongest signal is observed in pancreatic ductal adenocarcinoma (PDAC), where TNN mass-spec protein is more highly expressed in tumor relative to normal tissue. In most cancer types TNN is over-expressed in tumor, although a few such as CCRCC show the opposite, repressed pattern.
PDAC, CCRCC, and LUAD are the cancer types where TNN tumor–normal differential expression is most reproducible.