MAF and leiomyosarcoma: Although to our knowledge these genes have not been studied in GIST, a recent systems biological approach to identifying key transcriptional regulators in GIST and leiomyosarcoma identified nine differentially expressed genes, including the MYC gene, the MAF gene which encodes another basic leucine zipper (bZIP)-containing transcription factor closely related to MAFA, and another coiled-coil domain containing transcription factor gene, CCDC6 [60].