Figure 1. Sample collection and flow-chart of the study. A small number of cases were randomly selected as pilot studies and microarrays were performed. For saliva samples, the OSCC patient group (n=4) was compared with the HV group (n=4), and the expression levels of mRNA were compared. The expression levels of mRNA in tissue samples were compared between the OSCC tissue group (n=5) and the adjacent noncancerous tissues group (n=5). In saliva, there were 207 mRNAs that demonstrated a >2-fold change in the OSCC patient group, compared to the HV group. In tissue, there were 3,041 mRNAs that demonstrated >2- fold-change in the OSCC tissue group. Nine mRNAs that were upregulated more than 2-fold in both saliva and tissues were identified, and among these, NUS1 and RCN1 were selected for further investigation. HV: Healthy volunteers, OSCC: patients with oral squamous cell carcinoma.