The Texas Heart Institute Center for Cardiovascular Care has divulged piperazine-based integrin αLβ2 (LFA-1) and/or integrin α4β1 (ITGA4; VLA-4) agonists reported to be useful for the treatment of diabetes, infertility, pulmonary hypertension, renal failure, myocardial infarction, spinal cord injury, pulmonary fibrosis and Parkinson's diseases.