Poenie's research could generally be described as the cell biology of T lymphocytes. During T cell activation, a dramatic cytoskeletal rearrangement takes place that serves as a prelude to directional secretion. The key event in this process is the recruitment of the microtubule motor protein up to the contact site between the T cell and its target. The current study is of signaling events that trigger this rearrangement and recruits dyneing to the contact site.