parasites and growth factors
... Parasites will have to face physical factors like the contraction of muscles, chemical factors like a variety of proteolytic enzymes and of course, the power of the immune response. The parasite also will encounter host-derived humoral factors, including growth factors, that can be beneficial for the host leading to the elimination of the parasites, but it is also possible that they can directly or indirectly favor survival of the parasite in the initially hostile host environment. ... Of course the parasites have evolved in it’s presence and have developed different kind of strategies to evade these attacks. There are many factors produced to establish these interactions between the two of them. ... (1) The parasite can produce factors for its own use; (2) the parasite can produce factors to interact with the host; (3) the host can produce factors for its own use; and (4) the host can produce factors to interact with the parasite.