Examples of predicate-argument structures for group A As shown by Frame 1, PAS of mutate provided in PASBio contains more arguments than as suggested by PropBank [22, 23]. Extra arguments responsible for consequences of the event mutate are proposed to be core arguments as they are often seen in sentences from biomedical documents. WordNet  sense 1 – undergo mutation is correspond to biological sense we found for mutate. Three sentences are given to illustrate how surface sentences are mapped into PASBio's predicate-argument structure. Frame 2 shows predicate-argument structure of initiate which also belongs to group A – same sense, more arguments as same as predicate mutate. Extra arguments responsible for spatial information of the event intitate are proposed to be core arguments in PASBio, because of their importance from the perspective of biology as discussed in the main text.