<prompt> Chemoattractant is -C5aC1C3C2  <response>: - the transmigration of leucocytes after crossing several barriers to reach the interstitial tissue is a chemotactic factor mediated process called chemotaxis. - C5a and C3a are anaphylatoxins and powerful chemoattractant. Reference : Harsh mohan text book of pathology, 7 th edition,Pg no:120 p 