NHL is caused by long-term stimulation of the immune system. When B-cells multiply at a high rate for many years, more mutations occur. Some of these mutations cause cancer. So does long-term HIV infection. They are known by the initials of the drugs.
Chemotherapy is very toxic, and suppresses the immune system.
Common side effects include nausea, vomiting, fatigue, diarrhea, swollen and sensitive gums, mouth sores, hair loss, and numbness or tingling in the feet or hands. Chemotherapy can also damage bone marrow. Neutropenia can increase the risk of bacterial infections. More drugs are sometimes prescribed to fight these side effects. This is a treatment for neutropenia.