Air becomes trpped in alveoli 3. This condition is called emphysema. Basal cells ceep dividing but stop differentiating into columnar and goblet cells. Basal cells cross the basement membrane. Cells start to make an enzyme that breaks down the fibers in the basement membrane.
Tamoxifen acts like a hormone by binding to estrogen receptors.
A study was done on 13,000 high risk women. Half were given a placebo, just a pill that didn't have any drug in it and the other half were given tamoxifen. Then the study looked at how many people in each group ended up getting cancer. The group without tamoxifen had a chance of 1 out of 130 of getting breast cancer and the group with tamoxifen had a chance of 1 out of 236. So this showed that taking tamoxifen preventatively reduced a person's chance of getting breast cancer.