BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in BTB/POZ domain-containing protein 18 (BTBD18)
BTBD18 acts as a specific controller for transcription activation through RNA polymerase II elongation at a subset of genomic PIWI-interacting RNA (piRNA) loci. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.