Treemaps allows users to query data in the context of the entire GO classification with little loss of time. (A) The user rapidly determined that programmed cell death is represented by 48 gene nodes within the 5,529 gene nodes of the biological process GO classification (red circles in the data display and query window, and red box in the details of selected node). (B) Zooming enabled the identification of the Caspase co-factor Ark (Dark/Dapaf-1/Hac-1) as a possible significant factor in salivary gland cell death because of its large box 50.8333 fold-change in RNA level and red 0.0036 p-value (red circle in the data display and query window, and red box in details of selected node). Several other interesting cell death genes including the Caspases Nc (Dronc) and Ice (Drice), the Bcl-2 family member Buffy, the IAP th (Thread/Diap1), the CD36 family member crq, and the serine/threonine kinase Akt1 are present with significant red to orange p-values. (C-D) The black insignificant p-values for rpr (Reaper), W (Wrinkled/Hid) and Eip93F (E93) were rapidly assessed in the details of selected node, and the fact that all three of these genes are detected at extremely elevated levels 12 hours after puparium formation suggests that these p-values must be due to biological variation in RNA levels in either different cells or different salivary glands (red boxes).