The HepG2 cell lines transfected with siRNA directed to PCSK9 were challenged with Hcy, homocysteine thiolactone (HTL), testosterone, 5α-dihydroxytestosterone (5α-DHT), or estradiol for 24 h. Rats administered with Hcy developed HHcy and displayed PCOS-like phenotypes with adversely altered lipid homeostasis and attenuated PI3K-AKT and Wnt signalling cascade.