The second edition of this volume provides novel protocols for the study of newly discovered function and modifications of components of the Hh pathways. The first few chapters discuss methods for stable delivery of soluble Hh proteins in cell cultures that can be adapted for in vivo studies, and mathematical models for studying Hh proteins gradient formation in tissues. The next few chapters explore studies in cell culture using fibroblasts that respond readily to Hh proteins. The book goes on to present protocols for evaluation of transcriptional activity of the Gli transcription factors...