When these mice are used in conjunction with a Cre recombinase-expressing strain, successful Cre-mediated excision results in the constitutive expression of the Smo/EYFP fusion gene (monitored by using EYFP-specific fluorescence protocols) and unrestrained Hedgehog signaling in Cre-expressing tissues. As examples, this strain may be useful in studies of tumorigenic potential in the hedgehog pathway, progenitor cell involvement in the development of medulloblastomas, craniofacial development, thalamic development, and of oligodendrocyte maturation and CNS myelination when used in combination with specific cre-expressing strains. The Jackson Laboratory 2024, used with permission.