p120-catenin: Past and present.

p120-catenin was first described in 1989 as a Src substrate whose phosphorylation correlated with transformation. It was identified by cDNA cloning in 1992, and shown to interact with cadherins in 1994. Though enigmatic for some time, p120 has emerged as a master regulator of cadherin stability, and an important modulator of RhoGTPase activities. With the discovery of p120 family members and evidence for fundamental roles in cell biology and cancer, the field has expanded dramatically in recent years. As an introduction to this collection of reviews on p120 and its relatives, the editors have requested a personal commentary and historical perspective on the discovery of p120. The anecdotal parts have no particular purpose, but are mostly unpublished and perhaps of interest to some.