where x is the raw value to be converted, m is the mean of the population and s is the standard deviation (SD) of the population. The transformed value is denoted by z and exhibits positive value when the raw value is above mean and vice versa. Further, to examine the nuances and correlations masked in the full set of data, the z values are subjected to cluster analysis [55] to yield an ordered NumOfRows.x NumOfCols expression level matrix, E el . Hierarchical clustering is applied on the columns which represent the myriad of cytokine levels measurements (e.g.) based on McQuitty's or WPGMA method [56] where the distance between a pair of groups A and B is measured using the weighted arithmetic mean of all the pairwise distances between the data points in A and B. The rows which represent the suspected CHIKF patients and healthy individuals are left untouched. Seriation [57] is performed following the clustering approach to re-order the clustered data points using the minimum path length algorithm to minimize the sum of all the distances between adjacent columns.