Fact 1: Antigens are found on cancer cells and the cells of transplanted organs.

Fact 2: ALL proteins are antigens.

Given the two facts above, answer the question "What can be found on cancer cells?" with the following options: 
- acetic acid
 - Allergies
 - bacteria
 - parasites
 - fever
 - PDAs
 - proteins
 - bioaerosols


 

       proteins  