Step 1

Biochemistry 8

A 38-year-old woman presents to her physician to discuss genetic testing. She has no past medical history, but her mother died of breast cancer at age 42 years, and her sister was diagnosed with ovarian cancer at age 44 years. Genetic testing is ordered and reveals a mutation in the HER2 gene. Breast cancer is often caused by a mutation in the HER2 receptor/signaling mechanism.

This is an example of which of the following signaling pathways?

  • A) Adenylyl cyclase/cAMP/PKA
  • B) Guanalyl cyclase/cGMP/PKG
  • D) RTK/Ras/MAPK
  • E) TGF-beta/Smad


James McAllister


Dr. Ted O'Connell