Fig. 1.

Version 1 of a combined model for nuclear import of proteins, with nodes shown as rounded rectangles, with solid arrows illustrating causal dependencies (parent to child). Version 2 subsumes version 1 and adds parent to child dependencies as shown by dotted arrows. Modules of nodes are shaded to indicate the structure of the three basic models. Latent nodes have a dashed outline. Other nodes are labelled with the features that assign values to them, Boolean nodes have a thicker outline than continuous nodes.