the chemoattractants , formyl-methionyl-leucyl-phenylalanine ( fmlp ) , c5a , and leukotriene b4 ( ltb4 ) stimulated the gtpase in purified neutrophil plasma membrane preparations , whereas other secretagogues , such as a23187 and pma , were without effect .
C0008013
chemoattractants
C0027229
formyl-methionyl-leucyl-phenylalanine