In 1964, a group of scientists was using a microscope to study the cells of someone with a disease called Burkitt’s lymphoma. They saw small particles inside the cells and discovered they were viruses. This virus is now named Epstein-Barr virus, and it causes a disease called infectious mononucleosis, also known as the kissing disease. This is a tricky disease because it can have many symptoms that are also common to other diseases. Have you ever had a sore throat and fever? Maybe it was caused by Epstein-Barr virus! This virus mainly affects the cells of the lymphatic system, which defends the body from infections, so you can imagine why it is so interesting! Keep reading to learn more about this curious disease.