Predicate: retention
Roleset id: retention.01 , Keeping, vncls: , framnet:
retention.01: ~retain.01
Roles:
        Arg0: Keeper
        Arg1: Thing kept
        Arg3: Attributive (retained as)
Example: Arg0, 1
        person: ns,  tense: ns,  aspect: ns,  voice: ns,  form: ns
        Stimulated platelets use serotonin to enhance their retention of procoagulant proteins on the cell surface.
        Arg0: their
        Rel: retention
        Arg1: of procoagulant proteins on the cell curface