A small molecule gets produced by cells in one part of the body, circulates in the blood, estrogen enters cells, and sometimes that estrogen is able to penetrate deep within the cell, even into the nucleus.

雌激素是由身体某部分细胞分泌的,随着血液循环进入细胞,有时雌激素能够进入到细胞内部,甚至进入到细胞核内

耶鲁公开课 - 生物医学工程探索课程节选