The difficulty of comparing pocket predictions for many conformers of a protein. PASS (red) pocket predictions for an increasing number of conformers are superimposed onto a ribbon structure of human IL-2 [PDB:1M47]. From left to right, the results for 1, then 10 and 50 superimposed conformations. There is a greater spread of predicted pocket locations as the number of conformers increases. However, in this representation, the spread arises from both local structural variation of pockets and the different reorientation of each conformer required for the best global alignment.