Steroid sulfatase (STS) is a hydrolytic enzyme responsible for removing sulfate groups from steroid sulfates, thereby activating various steroid hormones. STS is primarily located on the endoplasmic reticulum membrane and is widely distributed in various tissues such as the liver, kidneys, skin, and placenta. STS plays a key role in regulating steroid hormone levels, reproductive system function, and skin metabolism. The specific expression and mutations of the gene are associated with various diseases, including X-linked ichthyosis, skin diseases (such as eczema and psoriasis), and certain cancers (such as breast and prostate cancer).