Abstract
One ubiquitous and very important signaling molecule inside cells is the phosphorylated lipid PtdIns(3,4,5)P. The biochemical pathways that deliver the signals from this lipid contain kinases (which add phosphates to other molecules) with regulatory properties that have seemed impossibly complex and diverse. In his commentary, Downward describes how new results reported in this week9s issue of Science ( Pullen et al. and Stephens et al.) and in Current Biology reveal that two of these kinases are actually regulated similarly, lending some welcome common themes to these pathways.