Non-Hodgkin lymphoma is a type of lymphoma. Lymphoma is cancer that affects the lymphatic system. The lymphatic system is made up of organs, glands, tubelike vessels and clusters of cells called lymph nodes. It's part of the body's germ-fighting immune system. The lymphatic system also includes the spleen, thymus, tonsils, adenoids and bone marrow. Non-Hodgkin lymphoma can affect all these areas and other organs in the body.

There are many types of lymphoma. Lymphoma types are often divided into two categories: Hodgkin lymphoma and non-Hodgkin lymphoma. Non-Hodgkin lymphoma is much more common than Hodgkin lymphoma. Non-Hodgkin lymphoma has many types that often begin in B cells or T cells.

• B cells. B cells are lymphocytes that fight infection. B cells make antibodies against foreign invaders of the body. Most non-Hodgkin lymphoma arises from B cells. Subtypes of non-Hodgkin lymphoma that involve B cells include diffuse large B-cell lymphoma, follicular lymphoma, mantle cell lymphoma and Burkitt lymphoma.

• T cells. T cells are lymphocytes that kill foreign invaders directly. Non-Hodgkin lymphoma happens much less often in T cells. Subtypes of non-Hodgkin lymphoma that involve T cells include peripheral T-cell lymphoma and cutaneous T-cell lymphoma.

Treatment depends on whether non-Hodgkin lymphoma arises from B cells or T cells. Treatments for non-Hodgkin lymphoma may include a "watch and wait" approach, chemotherapy, immunotherapy, and targeted therapy. Other treatments may include chimeric antigen receptor (CAR)-T cell therapy, bone marrow transplant, also called bone marrow stem cell transplant, and radiation therapy. (https://www.mayoclinic.org/diseases-conditions/non-hodgkins-lymphoma/symptoms-causes/syc-20375680)