c-Myc (also known as Myc), together with l-Myc and n-Myc, belongs to the Myc family of transcription factors. c-Myc has a basic helix-loop-helix leucine zipper domain and through heterodimerization can bind and regulate the transcriptional activity of genes, either by repression or activation. It is a key player in the regulation of cell growth and cell cycle progression and acts as a proto-oncogene. c-Myc is ubiquitously expressed in almost all cell types and its expression positively correlates with tissue proliferative capacity. c-Myc is also expressed during embryogenesis and is upregulated in many cancer types.
