As a result of producing anti-DDR1 antibodies and conducting extensive studies on the antitumor activity thereof, antibodies that bind to the stalk domain in the amino acid sequence of human DDR1 were found to have a potent activity even when used alone compared to antibodies that bind to other domains. It was also found that the antibodies have one or more activities selected from the group consisting of: (i) an activity to suppress cell proliferation, (ii) an activity to inhibit cell migration, (iii) an activity to inhibit phosphorylation of DDR1 in cells, (iv) an activity to be taken up into cells, (v) an activity to decrease the expression level of DDR1 in cells, and (vi) an activity to decrease the expression level of TGF-β in cells.
