Myc is a basic helix-loop-helix zipper transcription factor that regulates a network of many hundreds of genes. Myc up-regulates the expression of many genes involved in cell growth and proliferation such as ribosome biogenesis and protein synthesis (1). While many Myc induced genes are transcribed by RNA polymerase II, tRNA and rRNA genes are also Myc targets (1). Myc is also responsible for repressing genes involved in cell-cycle arrest and cell adhesion.
