Across TCGA pan-cancer cohorts, IGHD4-4 RNA differs between tumor and matched normal tissue in 4 of 18 cancer types tested, making tumor–normal expression one of IGHD4-4’s most consistent transcriptional readouts.
The strongest signal is observed in colon adenocarcinoma (COAD), where IGHD4-4 RNA is repressed in tumor relative to normal tissue. In most cancer types IGHD4-4 is over-expressed in tumor, although a few such as COAD show the opposite, repressed pattern.
COAD, LUAD, and KIRC are the cancer types where IGHD4-4 tumor–normal differential expression is most reproducible.