Transcription factor that facilitates establishment and maintenance of pluripotency in embryonic stem cells (ESCs) (PubMed:23942233, PubMed:26321140). With Klf2, acts as the major effector of self-renewal that mediates induction of pluripotency downstream of LIF/Stat3 and Wnt/beta-catenin signaling (PubMed:23942238, PubMed:23942233, PubMed:26321140). Required for normal duct development in the salivary gland and kidney (PubMed:17079272). Coordinates the development of the kidney collecting ducts intercalated (IC) and principal (PC) cells, which regulate acid-base and salt-water homeostasis, respectively (PubMed:28577314). Regulates the expression of IC genes including subunits B1 and D2 of the V-ATPase complex, Oxgr1, Ca12, Slc4a1, Aqp6 and IC-specific transcription factor Foxi1 (PubMed:28577314). Regulates also the expression of Jag1 and subsequent notch signaling in the collecting duct (PubMed:28577314). Jag1 initiates notch signaling in PCs but inhibits notch signaling in ICs (PubMed:28577314). Acts as a transcriptional suppressor that may suppress UBP1-mediated transcriptional activation (PubMed:11073954). Modulates the placental expression of CYP11A1 (By similarity). Forms homohexamers via its SAM-like domain (By similarity). Interacts with Mta1; which is indispensable for Tfcp2l1-mediated self-renewal-promoting effect and endoderm-inhibiting action (PubMed:28982712). Highly expressed in placenta, testis, small intestine, kidney and stomach (PubMed:11073954, PubMed:17079272). Low levels of expression in lung, mesenteric lymph nodes, muscle, ovary, and thymus (PubMed:11073954). No expression was detected in brain, heart, liver, and spleen (PubMed:11073954). Expressed in eccrine glands in the palm (PubMed:11073954). Expression is prominent in both kidney collecting ducts intercalated (IC) and principal (PC) cells (PubMed:28577314). Also expressed in the thick limb of Henle and connecting segments of the nephron (PubMed:28577314). Expressed at low levels in 10.5- and 11.5-dpc embryos. Expression was not detected at 12.5- and 13.5-dpc. Highly expressed in the epithelial monolayer lining in a subset of tubules of embryonic kidney cortex. Low levels of expression were detected in 16.5-dpc embryonic intestine, limb, lung, and skin. No expression was detected in the brain. Expression is regulated in at least two distinct sites, the pluripotent cells of the developing embryo and the epithelial cells lining the embryonic kidney distal convoluted tubules. Expressed in the ducts of submandibular and sublingual glands, isolated submandibular gland, parotid and lachrymal glands and nasal gland in 16 dpc embryos. At birth, the expression is detected in minor nasal glands in the olfactory epithelium, ducts of the mammary gland, male reproductive system, endolymphatic sac and lung. Expressed during renal development; first detected in the ureteric epithelium, at the distal end of the S-shaped body in nephron and subsequently in all nephric tubule, with expression localizing to more distal regions in the nephron during the maturation of the kidney. The Grh/CP2 DB domain is required for direct DNA-binding (By similarity). The Grh/CP2 DB domain is essential to maintain the undifferentiated state of embryonic stem cells (PubMed:28982712). The SAM-like domain is required for homohexamerization (By similarity). Approximately half of the mutant mice die before weaning and show growth retardation during early postnatal stages. Mice display defects in the morphology of the submandibular ducts, abnormalities in the maturation of renal tubules and abnormal composition of saliva and urine (PubMed:17079272). Leads to a decrease in the expression of pluripotency genes (Nanog, Oct4, Sox2 and Esrrb), while resulted in up-regulation of some endoderm (Sox17, Gata4 and Gata6), mesoderm (T and Mixl1) and trophectoderm (Cdx2, Eomes, and Elf5) markers (PubMed:28982712). Belongs to the grh/CP2 family. CP2 subfamily.