Gene Protein Reaction interactions. Gene Protein Reactions formulas for two Human Recon1 reactions. Each graph indicates the relationship between genes (purple), transcripts (magenta), protein (green), and reaction (teal). A) Sphingosine kinase 2 (SPHK21c) is associated with only one gene. B) Platelet-activating factor acetylhydrolase (PAFH) can be transcribed by either gene PAFAH2 or in combination of genes PAFAH1B1, PAFAH1B2, and PAFAH1B3. The GPR expression for this reaction is (5051.1) or (5049.1 and 5050.1) or (5049.1 and 5050.1 and 5048.1).