Across TCGA pan-cancer cohorts, GSTM1 RNA differs between tumor and matched normal tissue in 2 of 18 cancer types tested, making tumor–normal expression one of GSTM1’s most consistent transcriptional readouts.
The strongest signal is observed in uterine corpus endometrial carcinoma (UCEC), where GSTM1 RNA is repressed in tumor relative to normal tissue. In most cancer types GSTM1 is over-expressed in tumor, although a few such as UCEC and PRAD show the opposite, repressed pattern.
UCEC and PRAD are the cancer types where GSTM1 tumor–normal differential expression is most reproducible.