<span>When cells were first taken from Henrietta Lacks, she was suffering from cervix cancer. Henrietta Lacks was a woman whose cervix cancer cells were used as the source of the HeLa cell line nowadays used in medical research. During treatment for cervical cancer in 1951, the cells were taken without her knowledge. The cells were cultured by George Otto Gey who created the HeLa cell line.</span>
The answer is, "Lithosphere plate boundaries."
Most earth quakes occur in the upper 10-12 miles of the earth crust as the result of failure on faults caused by the strains induced by plate motions.
I hope this helps!