Box and whisker plots of EBV miRNA expression levels in sera determined using qPCR. Nine miRNAs were selected for qPCR based on their overexpression in FFPE NPC tissue. Box and whisker plots of the threshold cycle (Ct) values are shown for all miRNAs according to the geographical origin of the sera. MaC/MaN – Massachusetts control and test samples respectively (red); GC/GN – German control and test samples respectively (purple); and MC/MN – Malaysian control and test samples respectively (green). Boxes encompass the range between the upper and lower quartiles and whiskers extend to high/lowest values outside these bounds. Outliers, defined as greater/less than the upper/lower quartile by more than 1.5 times the interquartile range, are plotted as points.