alpha 2 beta 1 integrin is one of the most important collagen-binding receptors, and it has been implicated in numerous thrombotic and immune diseases. alpha 2 beta 1 integrin is a potent tumour suppressor, and its downregulation is associated with increased metastasis and poor prognosis in breast cancer. Currently, very little is known about the mechanism that regulates the cell-surface expression and trafficking of alpha 2 beta 1 integrin. Here, using a quantitative fluorescence-microscopy-based RNAi assay, we investigated the impact of 386 cytoskeleton-associated or -regulatory genes on alpha 2 integrin endocytosis and found that 122 of these affected the intracellular accumulation of alpha 2 integrin. Of these, 83 were found to be putative regulators of alpha 2 integrin trafficking and/or expression, with no observed effect on the internalization of epidermal growth factor (EGF) or transferrin. Further interrogation and validation of the siRNA screen revealed a role for KIF15, a microtubule-based molecular motor, as a significant inhibitor of the endocytic trafficking of alpha 2 integrin. Our data suggest a novel role for KIF15 in mediating plasma membrane localization of the alternative clathrin adaptor Dab2, thus impinging on pathways that regulate alpha 2 integrin internalization.