27-Hydroxycholesterol is primarily studied for its role in cholesterol metabolism and its implications in various diseases. It is known to act as an endogenous selective estrogen receptor modulator (SERM), influencing estrogen receptor activity in different tissues. This compound has been linked to the development and progression of atherosclerosis, as it promotes the accumulation of cholesterol in macrophages, leading to foam cell formation. Additionally, 27-Hydroxycholesterol is being investigated for its potential role in cancer, particularly breast cancer, where it may stimulate tumor growth by mimicking estrogen effects. Research also explores its involvement in neurodegenerative diseases, such as Alzheimer's, due to its ability to cross the blood-brain barrier and modulate neuronal cholesterol homeostasis. Its dual role in both cholesterol metabolism and hormone receptor signaling makes it a significant focus in understanding disease mechanisms and developing therapeutic strategies.