mast cells and alleviate the inflammation. there is evidence that etrolizumab is effective for ulcerative colitis, with phase 3 trials underway as of 2016. etrolizumab is a humanized monoclonal antibody that targets he β7 subunit of integrins α4β7 and αeβ7. etrolizumab decreases lymphocytes trafficking, similar to vedolizumab (another integrin antagonist). a type of leukocyte apheresis, known as granulocyte and monocyte adsorptive apheresis, still requires large-scale trials to determine whether or not it is effective. results from small trials have been tentatively positive.