Put the following events in the proper order of occurrence when RIK pathway of signal transduction is activated: 1. Signal transduction cascade 2. Autophosphorylation 3. Receptors dimerization 4. Gene expression 5. Ligand binding 2, 1,3,4,5 5 , 3 , 2 , 1 , 4 5 , 2 , 3 , 1 , 4 3 , 5 , 2 , 4 , 1.