William McGinnis is an American molecular biologist who is a professor of biology at the University of California San Diego.
He received his Ph.D. from UC Berkeley in 1982 and was a Jane Coffin Childs postdoctoral fellow at the University of Basel.
One long-term objective of the research in his lab is to understand the molecular interactions that underlie functional specificity in the Hox patterning system.
But importantly, for the discovery that Hox (homeobox) genes were found in vertebrates and a wide variety of animals, conserved, and were expressed in different regions of the vertebrate embryonic body axis, and that mammal Hox genes could function as anterior-posterior embryonic regulators of body axis specification, in flies as well as mammals.
That is, Hox gene functions were similar in controlling body axis patterning in both flies and other more complicated animals, such as mammals.