Fig. 4

Indigo naturalis treatment signature. (a) Hierarchical clustering diagram of baseline and post-Indigo naturalis treatment (week 8) samples of the entire study cohort; genes are represented as rows and samples as columns. Upregulated genes are shown in yellow and downregulated in blue. Samples from four different groups are denoted as follows: baseline lesional (BL_LS; blue), baseline nonlesional (BL_NL; green), week-8 Indigo naturalis-treated lesional (W8_LS_IND; purple), and week-8 placebo-treated (W8_LS_PLB; yellow); (b) a Venn diagram comparing moderate psoriasis gene signature (dark blue circle on the left) and Indigo naturalis treatment signature (light blue circle on the right); (c) enrichment of Ingenuity pathways by Indigo naturalis treatment gene signature. The stacked bar chart displays the number of up-regulated (red) and down-regulated (green) in each Ingenuity Canonical Pathway. The pathways are ranked by the p-value of a Fisher exact test from top to bottom (orange line; p-value listed in Additional file 3); (d) the “Role of IL-17A in psoriasis” pathway overlaid with the gene expression pattern and each circle represents one gene. Differential expression between lesional and nonlesional sample at baseline is shown in left-half of each circle, and differential expression between week 8 and baseline samples is shown in right- half of circles. Yellow = up-regulated, blue = down-regulated, IL = interleukin, RA, receptor A, RC, receptor C