The genes which lost perturbation ability showed enrichment in several important KEGG pathways such as p53 signaling pathway (hsa04115, 8.48 fold enrichment with 0.000002 p-value), Hepatitis B (hsa05161, 4.31 fold enrichment with 0.0002 p-value), and Cytokine-cytokine receptor interaction (hsa04060, 3.27 fold enrichment with 0.0003 p-value). Here, PPIB is linked to hepatitis A virus infection.