Philip Arden Beachy (born October 25, 1958)[3] is Ernest and Amelia Gallo Professor at Stanford University School of Medicine.

Nüsslein-Volhard's and Wieschaus's seminal 1980 study showed that hedgehog mutations cause unusual bristle patterns in Drosophila embryos.

He found, surprisingly, that during its production and release the Hedgehog protein autocatalytically cleaves itself and acquires two lipid modifications, cholesterol and palmitate.

With collaborators, Beachy demonstrated that addition of biochemically purified, functionally active Hedgehog protein to explanted embryonic tissues induced different cell-types in a concentration-dependent fashion.

[21] Human birth defects involving the limbs, skeleton, and other organs are also attributable to mutations affecting Hedgehog signaling.

Beachy showed that this Hedgehog-driven epithelial-mesenchymal feedback loop operates in many organs, including bladder, prostate, pancreas, and colon, thus suggesting new treatments for certain degenerative diseases and cancers.

Beachy noted the similarity to cyclopic Shh-/- mice[16] and in a brilliant leap demonstrated that cyclopamine inhibits Hedgehog signaling.

[27] Collectively, cyclopamine and other synthetic Hedgehog pathway modulators discovered by Beachy have provided a powerful and widely used pharmacological toolkit.

After receiving his Ph.D, he worked as an independent fellow (Staff Associate) at the Carnegie Institution's Department of Embryology in Baltimore for two years.

He then accepted a faculty position at the Johns Hopkins University School of Medicine and in the Howard Hughes Medical Institute.

He became interested in this field after reading a serialized form of Horace Freeland Judson's book, The Eighth Day of Creation in The New Yorker.

He then decided to attend graduate school at Stanford University and studied the molecular genetics of fruit fly development with David Hogness.