Transcriptional repressor that binds the core 5'GNNTGTNG-3' DNA consensus sequence (By similarity). Involved in megakaryocyte differentiation (By similarity). Self-associates. Interacts with other family members; IKZF1, IKZF2, IKZF3 AND IKZF4 (By similarity). The N-terminal zinc fingers are involved in sequence-specific DNA binding and heterotypic associations with other family members. C-terminal zinc fingers mediate homodimerization. 'Pegasus' was the winged horse in Greek mythology. Belongs to the Ikaros C2H2-type zinc-finger protein family.