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