Figure 2: Correlogram of baseline virological and immunological variables.
From: Immunological biomarkers predict HIV-1 viral rebound after treatment interruption

Heat maps and pie charts are used to indicate the strength of associations between potential biomarkers, with ordering determined by hierarchical clustering. Red indicates a negative correlation between the variables, blue a positive correlation. Size of pie and intensity of the colour indicates the strength of the association. Heat maps for associations with HIV-1 Total DNA are indicated with the red box.