18. Single sample gene set enrichment analysis (ssGSEA)

Single sample gene set enrichment analysis (ssGSEA) using the RSEM data from the knockdown and overexpression datasets was performed to identify the differentially expressed gene sets between conditions [18]. The GSVA enrichment scores in each sample were calculated by the “GSVA” package of R using the method “ssgesa” [19]. The top 50 gene sets significantly enriched in each dataset were extracted, clustered and visualized using the function “heatmap.2 of the “gplots” package of R.