positively regulates positive regulation of homotypic cell-cell adhesion biological regulation platelet aggregation regulation of platelet aggregation positive regulation of platelet aggregation activation of blood platelet aggregation positive regulation of blood platelet aggregation up-regulation of blood platelet aggregation activation of thrombocyte aggregation upregulation of blood platelet aggregation up regulation of platelet aggregation activation of platelet aggregation 2013-01-10T13:25:39Z upregulation of platelet aggregation up regulation of thrombocyte aggregation upregulation of thrombocyte aggregation up-regulation of thrombocyte aggregation up regulation of blood platelet aggregation up-regulation of platelet aggregation GO:1901731 Any process that activates or increases the frequency, rate or extent of platelet aggregation. Platelet aggregation is the adhesion of one platelet to one or more other platelets via adhesion molecules. positive regulation of thrombocyte aggregation