Figure 3
From: The diagnosis of inherited metabolic diseases by microarray gene expression profiling
Principal component analysis-effect of patient gender. There is no correspondence between PC1 and 2 and patient gender. A projection of all expression profiles onto the plane spanned by the first two PCs is shown. There is no clustering of male (blue) or female (red) arrays, indication that gender does not contribute substantially to gene expression variation. Grey = unknown; see also Additional file 2 'Samples').