The Immortal Life of Henrietta Lacks Chapter 25-28

Doctors discover another reason for Henrietta's cancer and unique cells: Human Papilloma Virus, or HPV. HPV was discovered to be able to cause cervical cancer and approximately 9 out of 10 sexually active adults carry it. The HeLa cells tested positive for the HPV virus. 

In the midst of a lawsuit, learning about her mother, and discovering that she has a younger sister in a mental institution, Deborah is pummeled by stress. By the end of chapter 28, Deborah suffers from a mental breakdown.