Saliva samples were incubated with or without RNAprotect Saliva Reagent at room temperature for 0 or 7 days. After RNA purification, samples were analyzed using Human Genome U133 Plus 2.0 GeneChip Arrays. Comparison between 0 and 7 days shows a 2-fold decrease in signal intensity for 159 transcripts with unstabilized samples, but for only 38 transcripts with RNAprotect stabilized samples (indicated by red spots). (Data kindly provided by Dr. David Wong, University of California, Los Angeles, CA, USA.)