Transcribed ultraconserved regions (T-UCRs) are a subset of 481 sequences longer than 200 bp, which are absolutely conserved between orthologous regions of human, rat and mouse genomes, and are actively transcribed. It has recently been proven in cancer systems that differentially expressed T-UCRs could alter the functional characteristics of malignant cells. Genome-wide profiling revealed that T-UCRs have distinct signatures in human leukemia and carcinoma