@misc{indiciaef00226fb666e,
  title = {Orchestrating ontogenesis: variations on a theme by sonic hedgehog.},
  author = {Philip W Ingham and Marysia Placzek},
  year = {2006},
  doi = {10.1038/nrg1969},
  url = {https://pubmed.ncbi.nlm.nih.gov/17047684/},
  note = {Source identifier: 17047684}
}