Estrogen Pathway When estrogen is docked to an estrogen receptor, a strong message is sent to multiply and divide breast cells in the replication and repair of breast tissue. Rapid replication of breast cells fueled by estrogen may result in an inadequate resting phase between subsequent cellular divisions. An inadequate resting phase between cellular divisions may result in the inability for newly formed cells to identify and eradicate genetic mutations. A mutated gene may result in the uncontrolled replication of breast cells in the formation of a cancerous mass. Estrogen further fuels the replication of mutated cells. Brevail Pathway When Brevail is docked to an estrogen receptor, a mild message is sent to multiply and divide breast cells in the replication and repair of breast tissue. Slower and controlled replication of breast cells may allow an adequate resting phase between subsequent cellular divisions. An adequate resting phase between cellular divisions may allow newly formed cells to identify and eradicate genetic mutations if present.