Table 1.

Core components of Hh pathway in Drosophila and vertebrates

Component Function	Protein Type	Drosophila Protein	Vertebrate Protein
Ligand	Secreted protein	Hedgehog (Hh)	Sonic Hedgehog (Shh), Desert Hedgehog (Dhh), Indian Hedgehog (Ihh)
Receptor	12-transmembrane protein	Patched (Ptc)	Patched1 (Ptch1), Patched2 (Ptch2)
Transcriptional activator and repressor	Zinc finger transcription factor	Cubitus interruptus (Ci)	Glioma-associated oncogene homologue (Gli1–3)
Signal activator	7-transmembrane protein, G-protein-coupled-receptor (GPCR)	Smoothened (Smo)	Smo
Signal transducer	Kinesin-like protein	Costal2 (Cos2)	Kinesin family member 7 (Kif7)
	Ser/Thr Kinase	Fused (Fu)	Fu/STK36
	PEST domain protein	Suppressor of Fused (Sufu)	Sufu