The PWWP domain is found in the BR140 family, which includes peregrin and BR140-like proteins 1 and 2. BR140 is the only family to contain the PWWP domain at the C terminus, with PHD and bromo domains in the N-terminal region. In myeloid leukemias, BR140 is disrupted by chromosomal translocations, similar to translocations of WHSC1 in lymphoid multiple myeloma. The PWWP domain, named for a conserved Pro-Trp-Trp-Pro motif, is a small domain consisting of 100-150 amino acids. The PWWP domain is found in numerous proteins that are involved in cell division, growth and differentiation. Most PWWP-domain proteins seem to be nuclear, often DNA-binding proteins, that function as transcription factors regulating a variety of developmental processes.