this factor probably is derived from the complement system since 1 ) its formation was associated with loss of c3 activity in human serum , 2 ) chemotactic factor , probably also a complement product , was generated simultaneously , 3 ) heat inactivation blocked its formation , 4 ) anti-c3 and anti-c5 blocked formation of the factor , and finally 5 ) anti-c5 inhibited the activity of the factor once it had been formed .
C0009499
complement
C0009498
complement