ESR1 and Hepatic cysts: Consistent with the effect of female gender and pregnancy in hepatic cyst growth [1, 17], it was found that estrogen receptor and insulin-like growth factor 1 (IGF1) receptor were markedly upregulated in hepatic cyst epithelium, and 17β-estradiol and IGF1 significantly promoted liver cyst-derived epithelial cell proliferation [19].