The present invention is directed to methods of using biomarkers to assess treatment of gastrointestinal inflammatory disorders with beta7 antagonists. More particularly, the present invention relates to methods of using the level of gut-homing lymphocytes in peripheral blood, the level of drug occupancy on gut-homing lymphocytes, and/or the level of beta7 integrin receptors on gut-homing lymphocytes as indicators (or biomarkers) of the effect, efficacy, safety, prognosis, and/or dosing of therapeutic agents, such as beta7 integrin antagonists, for the treatment of gastrointestinal inflammatory disorders.
