Transcription factor that acts as a key effector of the smoothened signaling pathway, and which plays a role in the development and patterning of various body structures, including the brain and limbs (PubMed:10075717, PubMed:10375510, PubMed:10693759, PubMed:11238441, PubMed:17764085, PubMed:20154143, PubMed:27146893). Specifically binds to the minimal GLI-consensus sequence 5'-GACCACCCA- 3' to activate or repress the expression of target genes (PubMed:10075717). Functions both as a transcriptional activator and repressor: the full-length GLI3 form (Transcription activator GLI3) acts as a transcription activator following smoothened activation, while the Transcription repressor GLI3R, which is generated in absence of smoothened, acts as a transcription repressor (PubMed:10375510). The repressor form (GLI3R) constitutes the major form of GLI3 (PubMed:10375510). {ECO:0000269|PubMed:10075717, ECO:0000269|PubMed:10375510, ECO:0000269|PubMed:10693759, ECO:0000269|PubMed:11238441, ECO:0000269|PubMed:17764085, ECO:0000269|PubMed:20154143, ECO:0000269|PubMed:27146893}. [Transcription repressor GLI3R]: Major transcription repressor, which inhibits expression of target genes in the absence of smoothened (SMO) signaling (PubMed:10375510, PubMed:10693759). Generated by proteolytic processing of the full-length GLI3 form in the absence of hedgehog (DHH, IHH or SHH), when SMO transducer is inhibited (PubMed:10375510). Constitutes the major form of GLI3, while the transcription activator form only plays a minor role (PubMed:10375510). . [Transcription activator GLI3]: Transcription factor, which activates expression of target genes in response to smoothened (SMO) activation (PubMed:10075717, PubMed:27146893). Constitutes a minor form of GLI3, while the transcription repressor form (GLI3R) plays a major role (PubMed:10075717). In concert with TRPS1, plays a role in regulating the size of the zone of distal chondrocytes, in restricting the zone of PTHLH expression in distal cells and in activating chondrocyte proliferation (PubMed:19389374). {ECO:0000269|PubMed:10075717, ECO:0000269|PubMed:19389374, ECO:0000269|PubMed:27146893}. This is the function of GLI3 (GLI family zinc finger 3, ENSG00000106571).