GLI3 and polysyndactyly 4: Mutations in the human GLI3 gene cause a variety of dominant developmental syndromes subsumed as "GLI3 morphopathies" [2,3], including Greig cephalopolysyndactyly syndrome (GCPS) [3-5], Pallister Hall syndrome (PHS) [6], postaxial polydactyly type A (PAPA) [7], and preaxial polydactyly type IV (PPD-IV) [2].