Amongst them, several KEGG pathways were closely related to PCOS, including TNF signalling pathway (hsa04668), HIF-1 signalling pathway (hsa04066), FoxO signalling pathway (hsa04068), PI3K-Akt signalling pathway (hsa04151), Toll-like receptor signalling pathway (hsa04620), T-cell receptor signalling pathway (hsa04660), VEGF signalling pathway (hsa04370), p53 signalling pathway (hsa04115), INS resistance (hsa04931), ErbB signalling pathway (hsa04012), and oestrogen signalling pathway (hsa04915). Here, EGFR is linked to polycystic ovary syndrome.