text: Pre-computed results for biological assemblies
  For a lot of proteins deposited in Protein Data Bank, the asymmetric unit might be different from biological unit, which would make the computational result biologically irrelevant. So the new CASTp 3.0 computed the topological features for biological assemblies, overcome the barriers between asymmetric unit and biological assemblies.
  Imprints of negative volumes of topological features
  In the 1st release of CASTp server in 2006, only geometric and topological features of those surface atoms participated in the formation of protein pockets, cavities, and channels. The new CASTp added the "negative volume" of the space, referred to the space encompassed by the atoms formed these geometric and topological features.
  Comprehensive annotation on single amino-acid polymorphism
  The latest CASTp integrated protein annotations aligned with the sequence, including the brief feature, positions, description, and reference of the domains, motifs, and single amino-acid polymorphisms.
  Improved user interface & convenient visualization
  The new CASTp now incorporated 3Dmol.js for structural visualization, made users able to browse, to interact the protein 3D model, and to examine the computational results in latest web-browsers including Chrome, Firefox, Safari, et al. Users can pick their own representation style of the atoms which form each topographic feature, and to edit the colors by their own preferences.