Methods for monitoring whether a subject will be sensitive or resistant to treatment with an anti-SMAD7 therapy are disclosed. The methods are based on the determining of the amount of CCR9+ FOXP3+ T cells, CCR9+ IFN-gamma+ T cells, CCR9+ IL17A+ T cells, FOXP3+ T cells, IFN-gamma+ T cells, and/or IL17A+ T cells in a sample from the subject. Measurement of T cell populations may be determined by flow cytometry, immunohistochemistry, and/or ELISA.