Figure 4. The OSCC staging by OPLS-DA according to the serum metabolic profiles. (A) The score plots of OSCC cases at different stages from T1 to T4. (B) The box plots for presenting the four lipid molecules’ relative abundance across HC and OSCC at different stages. (C) The average metabolite profiles of HC and T1-T4 OSCC subgroups. The metabolites were selected by their VIP scores.