- Evidence for a role for Galphai1 in mediating weak agonist-induced platelet aggregation in human platelets: reduced Galphai1 expression and defective Gi signaling in the platelets of a patient with a chronic bleeding disorder. Patel, Y.M., Patel, K., Rahman, S., Smith, M.P., Spooner, G., Sumathipala, R., Mitchell, M., Flynn, G., Aitken, A., Savidge, G. Blood (2003)