Fig. 2.

Hierarchical clustering analysis comparing cytokine production of acute CHIKV and DENV-infected patients revealed differential expression profiles between CHIKV and DENV as well as between DENV serotypes. Cytokines are ordered vertically by hierarchical clustering of the rows, which places cytokines with similar expression profiles closer together. Cytokine concentration of patients from the same group are collapsed by taking the mean inside each group and are ordered horizontally by hierarchical clustering so that groups with similar cytokine expression are closer to each other. Rows are centred and unit variance scaling is applied to rows. Therefore, cytokine concentrations are scaled such that a difference of 1 means that the values are one standard deviation away from the average of the row. Red, white, and blue indicates highest, middle, and lowest expression, respectively. Both rows and columns are clustered using Euclidean distance and average linkage