1.   Epstein has shown that overactivity of Sonic hedgehog is the cause of basal cell carcinoma, a common though treatable human skin cancer.

2.   Other viruses, however, could easily be developed to insert the Sonic hedgehog gene, Crystal said.

3.   Sonic hedgehog, and whatever other genes might be required, would have to induce thick enough hairs to be cosmetically significant.

4.   The new herald of hirsuteness is no mere cream or chemical but a gene with the strange and potent name of Sonic hedgehog.

5.   Epstein has found that overactivity of the Sonic hedgehog gene is a case of basal cell carcinoma, a common but treatable skin cancer.