Transcriptional regulator that binds to the promoter and activates the transcription of genes promoting brown adipose tissue (BAT) differentiation. Among brown adipose tissue-specific genes, binds the proximal region of the promoter of the UCP1 gene to activate its transcription and thereby regulate thermogenesis. May also play a role in the cellular response to replication stress (By similarity). Interacts with PRDM16; the interaction is direct and may play a role in the transcription of brown adipose tissue-specific genes (PubMed:25578880). Interacts with PWWP2B (PubMed:34180153). Interacts with HDAC1; this interaction is enhanced in the presence of PWWP2B (PubMed:34180153). Expressed by adipocytes more specifically in brown adipose tissue compared to white adipose tissue (WAT). Up-regulated in response to cold in brown and subcutaneous white adipose tissue where it may regulate non-shivering thermogenesis (at protein level). Knockout mice die immediately after birth. 20.5 dpc embryos display an impaired development of brown adipose tissue. Belongs to the krueppel C2H2-type zinc-finger protein family.