The myc family belongs to the basic helix-loop-helix leucine zipper class of transcription factors, see Pfam:PF00010. Myc forms a heterodimer with Max, and this complex regulates cell growth through direct activation of genes involved in cell replication [2]. Mutations in the C-terminal 20 residues of this domain cause unique changes in the induction of apoptosis, transformation, and G2 arrest [3].

1: The molecular role of Myc in growth and transformation: recent discoveries lead to new insights. Facchini LM, Penn LZ; FASEB J 1998;12:633-651. PMID:9619443

2: Myc target genes. Grandori C, Eisenman RN; Trends Biochem Sci 1997;22:177-181. PMID:9175477

3: A conserved Myc protein domain, MBIV, regulates DNA binding, apoptosis, transformation, and G2 arrest. Cowling VH, Chandriani S, Whitfield ML, Cole MD; Mol Cell Biol. 2006;26:4226-4239. PMID:16705173