Across TCGA pan-cancer cohorts, APOL5 RNA differs between tumor and matched normal tissue in 4 of 18 cancer types tested, making tumor–normal expression one of APOL5’s most consistent transcriptional readouts.
The strongest signal is observed in kidney renal clear cell carcinoma (KIRC), where APOL5 RNA is more highly expressed in tumor relative to normal tissue. In most cancer types APOL5 is over-expressed in tumor, although a few such as BRCA show the opposite, repressed pattern.
KIRC, BRCA, and KICH are the cancer types where APOL5 tumor–normal differential expression is most reproducible.