HDL-R: HDLS carry cholesterol to the liver for elimination. Liver cells respond to estrogen to express a protein receptor for HDLS coded by the HDL-R gene (HDL-R gene contains an estrogen response...

Extracted text: HDL-R: HDLS carry cholesterol to the liver for elimination. Liver cells respond to estrogen to express a protein receptor for HDLS coded by the HDL-R gene (HDL-R gene contains an estrogen response element.) PFK: codes for an enzyme called phosphofructokinase that is used in the first steps of breaking down glucose for energy in all cells. (Gene has no estrogen response element.) CD3: codes for a cell surface protein produced by immune B cells (Gene has no estrogen response element) If estrogen circulates and reaches all cells in the body, how is the HDL receptor protein produced in liver but not in immune cells? O Immune cells are not exposed to high enough levels of estrogen to stimulate transcription ofHDL-R into mRNA. O Immune cells have inactivated the estrogen response element in order to prevent expression of this genes that they don't need. O The HDL-R gene in immune cells lacks an estrogen response element in the upstream DNA. O Immune cells do not produce the estrogen receptor protein necessary to stimulate transcription of an estrogen-response element.